Revert "defconfigs: Disable RPC based RTC clock & enable PM8XXX RTC clock."

Causes issues with alarms

This reverts commit 44cf49a076956b3d2a27d6f87cf83eeed7ccc525.
Revert "mogami-board: add PM8XXX RTC clock"

Causes issues with alarms

This reverts commit 89e4b22c54357648268739f7d3f6fccfafa33502.

Change-Id: Ie97780fa22b51bab30121e22c908c521f9590acf
Signed-off-by: Michael Bestas <mikeioannina@gmail.com>