Revert "Circuitpython nickzoic 1046 nrf rtc"

[dhalbert]

Reverts #1534.

This breaks BLE:

>>> from adafruit_ble.uart import UARTServer
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "adafruit_ble/uart.py", line 34, in <module>
  File "adafruit_ble/uart.py", line 56, in UARTServer
OSError: Failed to change softdevice state

We'll need to check this out more thoroughly. Reverting so we can release a beta.6 with other fixes.

[tannewt]

Thank you! We can sort out the issue after Beta 6

[tannewt]

Merged because one build was ok. The LWIP git server isn't happy.

[nickzoic]

Ah, thanks Dan, I missed the cross-reference to this one! I'll make a new pull request ...