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)
diff --git a/src/soc/intel/skylake/Kconfig b/src/soc/intel/skylake/Kconfig
index ae86198..e22f1e3 100644
--- a/src/soc/intel/skylake/Kconfig
+++ b/src/soc/intel/skylake/Kconfig
@@ -52,6 +52,7 @@
 	select SOC_INTEL_COMMON_BLOCK
 	select SOC_INTEL_COMMON_BLOCK_GSPI
 	select SOC_INTEL_COMMON_BLOCK_PCR
+	select SOC_INTEL_COMMON_BLOCK_RTC
 	select SOC_INTEL_COMMON_BLOCK_SA
 	select SOC_INTEL_COMMON_BLOCK_XHCI
 	select SOC_INTEL_COMMON_LPSS_I2C