atmel-samd: Minor fixes to SysTick handler, enable all interrupts function.
atmel-samd: Minor fixes to SysTick handler, enable all interrupts function.

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