soc/intel/skylake: Use RTC common code

This patch uses common RTC library to enable
upper 128 byte bank of RTC RAM.

Change-Id: Ibcbaf5061e96a67815116a9f7a03be515997be6d
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/18701
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
2 files changed