docs/library/pyb.SPI: init(): Describe "bits" argument.
docs/library/pyb.SPI: init(): Describe "bits" argument.

Based on https://github.com/micropython/micropython/pull/2210 .

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