MM Communication PPI was defined in PI Specification since v1.5. This
change added definition of such PPI and related GUIDs into MdePkg.
Cc: Michael D Kinney <michael.d.kinney@intel.com> Cc: Liming Gao <gaoliming@byosoft.com.cn> Cc: Zhiguang Liu <zhiguang.liu@intel.com> Cc: Sean Brogan <sean.brogan@microsoft.com> Signed-off-by: Kun Qin <kuqin12@gmail.com> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>