soc/intel/common/pch: Make infrastructure ready for pch common code

This patch is intended to make Intel common PCH code based on
Gen-6 Sunrisepoint PCH (SPT).

All common PCH code blocks between Gen-6 till latest-PCH should be
part of soc/intel/common/pch/ directory.

A SoC Kconfig might select this option to include base PCH package
while building new SOC block. Currently majority of
common IP code blocks are part of soc/intel/common/block/ and
SoC Kconfig just select those Kconfig option. Now addition to that
SoC might only selects required base PCH block to include those
common IP block selections.

BUG=none
BRANCH=b:78109109
TEST=soc code can select PCH config option

Change-Id: I2934e3b1aed9d692eb00df18ce69a7fcd3096f6b
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/26348
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/common/Kconfig

@@ -8,6 +8,9 @@ if SOC_INTEL_COMMON
 comment "Intel SoC Common Code"
 source "src/soc/intel/common/block/Kconfig"
 
+comment "Intel SoC Common PCH Code"
+source "src/soc/intel/common/pch/Kconfig"
+
 config DISPLAY_MTRRS
 	bool "MTRRs: Display the MTRR settings"
 	default n