switch nvm.ByteArray to use new nrf_nvm_safe_flash_page_write
switch nvm.ByteArray to use new nrf_nvm_safe_flash_page_write

adafruit/circuitpython#1610

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