nrf/main: Add auto mount and auto format hook for internal flash FS.
nrf/main: Add auto mount and auto format hook for internal flash FS.

adafruit/circuitpython,bvernoux/micropython,bvernoux/micropython,bvernoux/micropython,bvernoux/micropython,bvernoux/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython