IntelSiliconPkg: Move MicrocodeUpdate from UefiCpuPkg

IntelSiliconPkg: Move MicrocodeUpdate from UefiCpuPkg

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=540

To consume FIT table for Microcode update,
UefiCpuPkg/Feature/Capsule/MicrocodeUpdateDxe
needs to be updated to consume
IntelSiliconPkg/Include/IndustryStandard/FirmwareInterfaceTable.h,
but UefiCpuPkg could not depend on IntelSiliconPkg.

Since the Microcode update feature is specific to Intel,
we can first move the Microcode update feature code from
UefiCpuPkg to IntelSiliconPkg [first step], then update
the code to consume FIT table [second step].

This patch series is for the first step.

Note: No any code change in this patch, just move.
Next patch will update MicrocodeUpdate to build with the package.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>