MdePkg: MmCommunication: Added definition of MM Communication PPI

MdePkg: MmCommunication: Added definition of MM Communication PPI

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3629

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>