stm32/adc: Use mp_hal_pin_config() instead of HAL_GPIO_Init().
stm32/adc: Use mp_hal_pin_config() instead of HAL_GPIO_Init().

This makes ADCAll work correctly on L4 MCUs.

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