stm32/rtc: Add RTC support for H7 MCUs.
stm32/rtc: Add RTC support for H7 MCUs.

pozetroninc/micropython,adafruit/circuitpython,pramasoul/micropython,adafruit/circuitpython,MrSurly/micropython,pramasoul/micropython,tralamazza/micropython,trezor/micropython,ryannathans/micropython,selste/micropython,pfalcon/micropython,swegener/micropython,tralamazza/micropython,bvernoux/micropython,selste/micropython,henriknelson/micropython,MrSurly/micropython,kerneltask/micropython,henriknelson/micropython,MrSurly/micropython,swegener/micropython,adafruit/circuitpython,ryannathans/micropython,pramasoul/micropython,swegener/micropython,tobbad/micropython,adafruit/micropython,henriknelson/micropython,dmazzella/micropython,pfalcon/micropython,trezor/micropython,tobbad/micropython,adafruit/micropython,trezor/micropython,bvernoux/micropython,adafruit/micropython,ryannathans/micropython,adafruit/circuitpython,tobbad/micropython,bvernoux/micropython,pozetroninc/micropython,MrSurly/micropython,ryannathans/micropython,henriknelson/micropython,selste/micropython,adafruit/micropython,pfalcon/micropython,henriknelson/micropython,pozetroninc/micropython,pramasoul/micropython,kerneltask/micropython,pramasoul/micropython,selste/micropython,bvernoux/micropython,swegener/micropython,trezor/micropython,pozetroninc/micropython,adafruit/circuitpython,adafruit/circuitpython,tralamazza/micropython,tralamazza/micropython,bvernoux/micropython,swegener/micropython,pozetroninc/micropython,trezor/micropython,dmazzella/micropython,adafruit/micropython,selste/micropython,dmazzella/micropython,ryannathans/micropython,kerneltask/micropython,dmazzella/micropython,kerneltask/micropython,MrSurly/micropython,tobbad/micropython,kerneltask/micropython,pfalcon/micropython,pfalcon/micropython,tobbad/micropython