py/mphal.h: Provide default prototypes for mp_hal_delay_us/mp_hal_ticks_us.
py/mphal.h: Provide default prototypes for mp_hal_delay_us/mp_hal_ticks_us.

Similar to existing mp_hal_delay_ms/mp_hal_ticks_ms.

adafruit/circuitpython,selste/micropython,jmarcelino/pycom-micropython,lowRISC/micropython,oopy/micropython,mpalomer/micropython,toolmacher/micropython,praemdonck/micropython,redbear/micropython,PappaPeppar/micropython,cwyark/micropython,torwag/micropython,emfcamp/micropython,drrk/micropython,micropython/micropython-esp32,swegener/micropython,SHA2017-badge/micropython-esp32,deshipu/micropython,tobbad/micropython,ganshun666/micropython,Timmenem/micropython,tuc-osg/micropython,dmazzella/micropython,ganshun666/micropython,turbinenreiter/micropython,jmarcelino/pycom-micropython,dinau/micropython,pozetroninc/micropython,hiway/micropython,MrSurly/micropython,turbinenreiter/micropython,alex-march/micropython,toolmacher/micropython,hiway/micropython,deshipu/micropython,lowRISC/micropython,TDAbboud/micropython,matthewelse/micropython,pfalcon/micropython,tralamazza/micropython,pfalcon/micropython,alex-march/micropython,blazewicz/micropython,bvernoux/micropython,deshipu/micropython,AriZuu/micropython,mpalomer/micropython,pramasoul/micropython,puuu/micropython,Peetz0r/micropython-esp32,oopy/micropython,dmazzella/micropython,oopy/micropython,turbinenreiter/micropython,tobbad/micropython,dinau/micropython,tralamazza/micropython,TDAbboud/micropython,pfalcon/micropython,dxxb/micropython,henriknelson/micropython,redbear/micropython,swegener/micropython,adafruit/circuitpython,mhoffma/micropython,MrSurly/micropython-esp32,micropython/micropython-esp32,mpalomer/micropython,HenrikSolver/micropython,infinnovation/micropython,turbinenreiter/micropython,blazewicz/micropython,redbear/micropython,puuu/micropython,micropython/micropython-esp32,cwyark/micropython,Peetz0r/micropython-esp32,adafruit/micropython,trezor/micropython,tobbad/micropython,oopy/micropython,alex-robbins/micropython,infinnovation/micropython,tobbad/micropython,turbinenreiter/micropython,lowRISC/micropython,tuc-osg/micropython,adafruit/micropython,praemdonck/micropython,lowRISC/micropython,deshipu/micropython,dxxb/micropython,redbear/micropython,chrisdearman/micropython,matthewelse/micropython,MrSurly/micropython-esp32,swegener/micropython,alex-march/micropython,pramasoul/micropython,mpalomer/micropython,Peetz0r/micropython-esp32,AriZuu/micropython,torwag/micropython,cwyark/micropython,alex-march/micropython,MrSurly/micropython,mpalomer/micropython,ganshun666/micropython,jmarcelino/pycom-micropython,kerneltask/micropython,kerneltask/micropython,torwag/micropython,toolmacher/micropython,pozetroninc/micropython,praemdonck/micropython,tobbad/micropython,pramasoul/micropython,puuu/micropython,henriknelson/micropython,dxxb/micropython,kerneltask/micropython,HenrikSolver/micropython,hosaka/micropython,Timmenem/micropython,tralamazza/micropython,henriknelson/micropython,praemdonck/micropython,hiway/micropython,ganshun666/micropython,pramasoul/micropython,tralamazza/micropython,alex-robbins/micropython,dinau/micropython,toolmacher/micropython,TDAbboud/micropython,MrSurly/micropython-esp32,drrk/micropython,ryannathans/micropython,hiway/micropython,alex-march/micropython,ryannathans/micropython,adafruit/circuitpython,trezor/micropython,drrk/micropython,AriZuu/micropython,cwyark/micropython,emfcamp/micropython,bvernoux/micropython,dxxb/micropython,hiway/micropython,alex-robbins/micropython,hosaka/micropython,HenrikSolver/micropython,pfalcon/micropython,blazewicz/micropython,Timmenem/micropython,Timmenem/micropython,selste/micropython,adafruit/circuitpython,jmarcelino/pycom-micropython,adafruit/micropython,selste/micropython,praemdonck/micropython,emfcamp/micropython,puuu/micropython,hosaka/micropython,dxxb/micropython,tuc-osg/micropython,AriZuu/micropython,SHA2017-badge/micropython-esp32,ryannathans/micropython,TDAbboud/micropython,tuc-osg/micropython,Timmenem/micropython,adafruit/circuitpython,henriknelson/micropython,SHA2017-badge/micropython-esp32,lowRISC/micropython,dinau/micropython,matthewelse/micropython,torwag/micropython,bvernoux/micropython,pozetroninc/micropython,infinnovation/micropython,emfcamp/micropython,HenrikSolver/micropython,chrisdearman/micropython,mhoffma/micropython,PappaPeppar/micropython,chrisdearman/micropython,henriknelson/micropython,trezor/micropython,torwag/micropython,dmazzella/micropython,dinau/micropython,PappaPeppar/micropython,kerneltask/micropython,puuu/micropython,ganshun666/micropython,mhoffma/micropython,oopy/micropython,cwyark/micropython,pozetroninc/micropython,PappaPeppar/micropython,mhoffma/micropython,hosaka/micropython,pozetroninc/micropython,MrSurly/micropython,hosaka/micropython,AriZuu/micropython,matthewelse/micropython,TDAbboud/micropython,redbear/micropython,drrk/micropython,mhoffma/micropython,bvernoux/micropython,MrSurly/micropython,pramasoul/micropython,MrSurly/micropython-esp32,toolmacher/micropython,HenrikSolver/micropython,infinnovation/micropython,drrk/micropython,MrSurly/micropython-esp32,alex-robbins/micropython,tuc-osg/micropython,SHA2017-badge/micropython-esp32,blazewicz/micropython,chrisdearman/micropython,trezor/micropython,pfalcon/micropython,chrisdearman/micropython,ryannathans/micropython,bvernoux/micropython,Peetz0r/micropython-esp32,infinnovation/micropython,trezor/micropython,blazewicz/micropython,adafruit/micropython,micropython/micropython-esp32,ryannathans/micropython,SHA2017-badge/micropython-esp32,deshipu/micropython,kerneltask/micropython,alex-robbins/micropython,selste/micropython,Peetz0r/micropython-esp32,matthewelse/micropython,jmarcelino/pycom-micropython,emfcamp/micropython,matthewelse/micropython,micropython/micropython-esp32,dmazzella/micropython,swegener/micropython,adafruit/micropython,PappaPeppar/micropython,MrSurly/micropython,selste/micropython,adafruit/circuitpython,swegener/micropython