stmhal: M7 Reset clocksources changed by DFU bootloader
stmhal: M7 Reset clocksources changed by DFU bootloader

The DFU bootloader on the ST32F7 chip changes the clocksource
for various possible boot sources (UART1, UART3, I2C1-3).
This commit resets those clock sources back to their cold
reset values.

TDAbboud/micropython,turbinenreiter/micropython,utopiaprince/micropython,mianos/micropython,henriknelson/micropython,pramasoul/micropython,SHA2017-badge/micropython-esp32,xyb/micropython,xyb/micropython,bvernoux/micropython,micropython/micropython-esp32,firstval/micropython,adafruit/micropython,rubencabrera/micropython,HenrikSolver/micropython,blazewicz/micropython,ahotam/micropython,cloudformdesign/micropython,stonegithubs/micropython,SHA2017-badge/micropython-esp32,neilh10/micropython,infinnovation/micropython,rubencabrera/micropython,praemdonck/micropython,danicampora/micropython,ericsnowcurrently/micropython,Timmenem/micropython,alex-robbins/micropython,adamkh/micropython,pfalcon/micropython,emfcamp/micropython,HenrikSolver/micropython,deshipu/micropython,jlillest/micropython,lowRISC/micropython,dhylands/micropython,dxxb/micropython,puuu/micropython,Peetz0r/micropython-esp32,kerneltask/micropython,vitiral/micropython,dxxb/micropython,ryannathans/micropython,danicampora/micropython,xhat/micropython,rubencabrera/micropython,blazewicz/micropython,swegener/micropython,stonegithubs/micropython,tobbad/micropython,alex-march/micropython,cwyark/micropython,pozetroninc/micropython,mianos/micropython,redbear/micropython,mpalomer/micropython,oopy/micropython,hiway/micropython,ChuckM/micropython,rubencabrera/micropython,utopiaprince/micropython,supergis/micropython,feilongfl/micropython,puuu/micropython,tuc-osg/micropython,chrisdearman/micropython,xyb/micropython,kostyll/micropython,bvernoux/micropython,SHA2017-badge/micropython-esp32,blmorris/micropython,mgyenik/micropython,ruffy91/micropython,vitiral/micropython,mhoffma/micropython,tralamazza/micropython,tralamazza/micropython,adafruit/circuitpython,danicampora/micropython,tuc-osg/micropython,martinribelotta/micropython,pramasoul/micropython,adafruit/circuitpython,oopy/micropython,hosaka/micropython,toolmacher/micropython,deshipu/micropython,infinnovation/micropython,noahwilliamsson/micropython,pfalcon/micropython,turbinenreiter/micropython,vitiral/micropython,MrSurly/micropython,puuu/micropython,MrSurly/micropython-esp32,noahwilliamsson/micropython,lowRISC/micropython,ceramos/micropython,vitiral/micropython,ryannathans/micropython,mhoffma/micropython,emfcamp/micropython,supergis/micropython,jlillest/micropython,ChuckM/micropython,trezor/micropython,noahchense/micropython,alex-robbins/micropython,ericsnowcurrently/micropython,ganshun666/micropython,TDAbboud/micropython,hiway/micropython,emfcamp/micropython,firstval/micropython,pozetroninc/micropython,matthewelse/micropython,cloudformdesign/micropython,torwag/micropython,ChuckM/micropython,hosaka/micropython,cloudformdesign/micropython,PappaPeppar/micropython,SHA2017-badge/micropython-esp32,mpalomer/micropython,cwyark/micropython,HenrikSolver/micropython,tralamazza/micropython,PappaPeppar/micropython,trezor/micropython,Peetz0r/micropython-esp32,AriZuu/micropython,jmarcelino/pycom-micropython,vitiral/micropython,skybird6672/micropython,ruffy91/micropython,xuxiaoxin/micropython,ericsnowcurrently/micropython,orionrobots/micropython,omtinez/micropython,ganshun666/micropython,ernesto-g/micropython,adamkh/micropython,orionrobots/micropython,mianos/micropython,swegener/micropython,neilh10/micropython,kostyll/micropython,trezor/micropython,EcmaXp/micropython,xhat/micropython,redbear/micropython,bvernoux/micropython,noahchense/micropython,omtinez/micropython,galenhz/micropython,ceramos/micropython,misterdanb/micropython,ChuckM/micropython,xuxiaoxin/micropython,MrSurly/micropython,dxxb/micropython,ceramos/micropython,xuxiaoxin/micropython,drrk/micropython,dxxb/micropython,mhoffma/micropython,xyb/micropython,dinau/micropython,lowRISC/micropython,ahotam/micropython,ryannathans/micropython,swegener/micropython,praemdonck/micropython,tobbad/micropython,hosaka/micropython,vriera/micropython,supergis/micropython,redbear/micropython,mianos/micropython,orionrobots/micropython,matthewelse/micropython,ernesto-g/micropython,trezor/micropython,tuc-osg/micropython,ceramos/micropython,turbinenreiter/micropython,mpalomer/micropython,noahchense/micropython,lowRISC/micropython,dmazzella/micropython,utopiaprince/micropython,vriera/micropython,adafruit/circuitpython,Timmenem/micropython,mgyenik/micropython,martinribelotta/micropython,dhylands/micropython,adafruit/circuitpython,kostyll/micropython,infinnovation/micropython,mgyenik/micropython,EcmaXp/micropython,vriera/micropython,jlillest/micropython,stonegithubs/micropython,cnoviello/micropython,adamkh/micropython,skybird6672/micropython,noahwilliamsson/micropython,utopiaprince/micropython,micropython/micropython-esp32,drrk/micropython,turbinenreiter/micropython,dinau/micropython,MrSurly/micropython-esp32,Peetz0r/micropython-esp32,mgyenik/micropython,mhoffma/micropython,skybird6672/micropython,Timmenem/micropython,skybird6672/micropython,adafruit/micropython,hosaka/micropython,deshipu/micropython,henriknelson/micropython,kerneltask/micropython,dinau/micropython,mpalomer/micropython,cloudformdesign/micropython,henriknelson/micropython,heisewangluo/micropython,feilongfl/micropython,tobbad/micropython,ahotam/micropython,EcmaXp/micropython,jmarcelino/pycom-micropython,swegener/micropython,ernesto-g/micropython,torwag/micropython,cnoviello/micropython,lowRISC/micropython,hiway/micropython,jlillest/micropython,firstval/micropython,misterdanb/micropython,toolmacher/micropython,stonegithubs/micropython,emfcamp/micropython,puuu/micropython,alex-march/micropython,neilh10/micropython,cloudformdesign/micropython,adafruit/circuitpython,ernesto-g/micropython,selste/micropython,cnoviello/micropython,misterdanb/micropython,martinribelotta/micropython,matthewelse/micropython,alex-march/micropython,blazewicz/micropython,mgyenik/micropython,bvernoux/micropython,infinnovation/micropython,selste/micropython,galenhz/micropython,ryannathans/micropython,pramasoul/micropython,AriZuu/micropython,oopy/micropython,adafruit/micropython,ernesto-g/micropython,jlillest/micropython,alex-robbins/micropython,neilh10/micropython,xhat/micropython,ericsnowcurrently/micropython,dmazzella/micropython,oopy/micropython,neilh10/micropython,PappaPeppar/micropython,omtinez/micropython,ruffy91/micropython,kerneltask/micropython,supergis/micropython,pozetroninc/micropython,AriZuu/micropython,henriknelson/micropython,firstval/micropython,TDAbboud/micropython,dhylands/micropython,kostyll/micropython,galenhz/micropython,noahwilliamsson/micropython,pfalcon/micropython,oopy/micropython,alex-robbins/micropython,MrSurly/micropython,redbear/micropython,matthewelse/micropython,emfcamp/micropython,adafruit/micropython,torwag/micropython,ganshun666/micropython,skybird6672/micropython,mpalomer/micropython,tobbad/micropython,HenrikSolver/micropython,pozetroninc/micropython,alex-march/micropython,PappaPeppar/micropython,MrSurly/micropython-esp32,micropython/micropython-esp32,drrk/micropython,mhoffma/micropython,selste/micropython,blazewicz/micropython,pozetroninc/micropython,adafruit/micropython,omtinez/micropython,danicampora/micropython,toolmacher/micropython,heisewangluo/micropython,stonegithubs/micropython,xyb/micropython,selste/micropython,micropython/micropython-esp32,xuxiaoxin/micropython,turbinenreiter/micropython,chrisdearman/micropython,martinribelotta/micropython,cwyark/micropython,tobbad/micropython,noahwilliamsson/micropython,blmorris/micropython,praemdonck/micropython,MrSurly/micropython,dmazzella/micropython,micropython/micropython-esp32,jmarcelino/pycom-micropython,alex-robbins/micropython,toolmacher/micropython,tuc-osg/micropython,praemdonck/micropython,hiway/micropython,dmazzella/micropython,ahotam/micropython,cnoviello/micropython,Timmenem/micropython,jmarcelino/pycom-micropython,AriZuu/micropython,jmarcelino/pycom-micropython,EcmaXp/micropython,dinau/micropython,bvernoux/micropython,HenrikSolver/micropython,tralamazza/micropython,drrk/micropython,MrSurly/micropython-esp32,noahchense/micropython,AriZuu/micropython,adamkh/micropython,MrSurly/micropython-esp32,puuu/micropython,kostyll/micropython,dxxb/micropython,blmorris/micropython,hiway/micropython,heisewangluo/micropython,dinau/micropython,pfalcon/micropython,ganshun666/micropython,feilongfl/micropython,dhylands/micropython,henriknelson/micropython,noahchense/micropython,MrSurly/micropython,torwag/micropython,toolmacher/micropython,swegener/micropython,galenhz/micropython,Peetz0r/micropython-esp32,adamkh/micropython,kerneltask/micropython,pramasoul/micropython,tuc-osg/micropython,ganshun666/micropython,EcmaXp/micropython,xhat/micropython,heisewangluo/micropython,PappaPeppar/micropython,Timmenem/micropython,vriera/micropython,dhylands/micropython,misterdanb/micropython,chrisdearman/micropython,Peetz0r/micropython-esp32,blmorris/micropython,galenhz/micropython,rubencabrera/micropython,torwag/micropython,TDAbboud/micropython,ruffy91/micropython,deshipu/micropython,deshipu/micropython,ChuckM/micropython,cwyark/micropython,firstval/micropython,infinnovation/micropython,chrisdearman/micropython,xuxiaoxin/micropython,ryannathans/micropython,hosaka/micropython,martinribelotta/micropython,praemdonck/micropython,TDAbboud/micropython,ceramos/micropython,mianos/micropython,redbear/micropython,orionrobots/micropython,trezor/micropython,orionrobots/micropython,heisewangluo/micropython,SHA2017-badge/micropython-esp32,drrk/micropython,pfalcon/micropython,chrisdearman/micropython,utopiaprince/micropython,misterdanb/micropython,kerneltask/micropython,cnoviello/micropython,alex-march/micropython,feilongfl/micropython,danicampora/micropython,ruffy91/micropython,vriera/micropython,ericsnowcurrently/micropython,adafruit/circuitpython,matthewelse/micropython,matthewelse/micropython,blazewicz/micropython,feilongfl/micropython,supergis/micropython,blmorris/micropython,omtinez/micropython,cwyark/micropython,ahotam/micropython,xhat/micropython,selste/micropython,pramasoul/micropython