nrf5/hal: Adding structures and init function prototype to hal_rtc.h.
nrf5/hal: Adding structures and init function prototype to hal_rtc.h.

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