stm32/i2c: Fix num_acks calculation in i2c_write for F0 and F7 MCU's.
stm32/i2c: Fix num_acks calculation in i2c_write for F0 and F7 MCU's.

Due to buffering of outgoing bytes on the I2C bus, detection of a NACK
using the ISR_NACKF flag needs to account for the case where ISR_NACKF
corresponds to the previous-to-previous byte.

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