Features/Intel/PlatformPayloadPkg: add platform payload FV

UefiPayloadPkg in EDK2 repo was added SMM variable support for Intel
platform with SPI flash. But some of the modules for SMM variable are
Intel PCH specific (e.g. SPI library, SMM PCH module), so move these
modules into edk2-platforms repo.

A platform payload FV could be built from PlatformPayloadPkg which works
on Intel platforms (e.g.. ICX, APL, CML, CFL, KBL, TGL, ADL, etc.) with
SMM variable. This platform payload FV could be added into universal UEFI
payload built from EDK2 UefiPayloadPkg.

The steps to build a complete payload (use windows host as example):

set WORKSPACE=c:\payload
set PACKAGES_PATH=C:\payload\edk2;C:\payload\edk2-platforms\Platform\Intel;
C:\payload\edk2-platforms\Features\Intel;
edk2\edksetup.bat

python edk2\UefiPayloadPkg\UniversalPayloadBuild.py -t VS2019
 -D SMM_SUPPORT=TRUE -DVARIABLE_SUPPORT=NONE

python edk2-platforms\Features\Intel\PlatformPayloadPkg\PlatformPayloadPkg.py
 -t VS2019 -D SMM_VARIABLE=TRUE -s

The final UEFI payload generated at Build\UefiPayloadPkgX64\UniversalPayload.elf
if build success.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Sean Rhodes <sean@starlabs.systems>
Signed-off-by: Guo Dong <guo.dong@intel.com>
Signed-off-by: Isaac Oram <isaac.w.oram@intel.com>
Reviewed-by: Sai Chaganty <rangasai.v.chaganty@intel.com>