atmel-samd: Use our own CDC output cache because the internal (#366)
atmel-samd: Use our own CDC output cache because the internal (#366)

atmel-samd: Use our own CDC output cache because the internal
cache is only used when the memory isn't aligned even if we're
going to change the memory immediately after.
adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython,adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython