UefiCpuPkg/PiSmmCpuDxeSmm: Add support for PCD PcdPteMemoryEncryptionAddressOrMask

This PCD holds the address mask for page table entries when memory
encryption is enabled on AMD processors supporting the Secure Encrypted
Virtualization (SEV) feature.

The mask is applied when page tables entriees are created or modified.

CC: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Leo Duran <leo.duran@amd.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>