enable use of CIRCUITPY_CANARY_WORD (needed for 2.2 merge) (#513)
enable use of CIRCUITPY_CANARY_WORD (needed for 2.2 merge) (#513)

enable use of CIRCUITPY_CANARY_WORD (needed for 2.2 merge)

RCAUSE (reset cause) is fetched differently in SAMD21 vs SAMD51

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