stm32/modmachine: In bootloader() disable caches before reset of periphs
stm32/modmachine: In bootloader() disable caches before reset of periphs

Otherwise flushing and disabling the D-cache will give a hard-fault when
SDRAM is used.

Fixes #4818.

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