soc/intel/common/block: Update common rtc code

Move rtc init code into common area and update the implementation for
apollolake to avoid build break.

Change-Id: I702ce0efba25cb6fde33cc15698ae44312742367
Signed-off-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-on: https://review.coreboot.org/21433
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
4 files changed