supervisor/shared/external_flash/devices.h: Add MX25L51245G support.
supervisor/shared/external_flash/devices.h: Add MX25L51245G support.

Add external flash support for Macronix MX25L51245G 64MiB SPI flash.

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