Revert "rtc: alarm: Proper handling of spinlock"

Improper handling ultimately breaks reboot to recovery/download.

This reverts commit 537d9288198b49c04206981949ad875a3d3d9d91.

Change-Id: I603b463625d6a31a5ed3caaf219b0a36d180fdbe
rtc: alarm: Proper handling of spinlock

Real proper.

Change-Id: I58c01e5d307dfbafa8e8bdad71c4521212524bbb