Commit aef50446ce
removed gEdkiiPeiMpServices2PpiGuid from UefiCpuPkg.dec
which causes build breaks if an INF [Ppis] section
lists gEdkiiPeiMpServices2PpiGuid. There is no method
for a DEC file for conditionally declare a PPI.
In order to support the migration from use of
gEdkiiPeiMpServices2PpiGuid to the preferred use of the
gPeiMpServices2Ppi, update MpServices2.h in MdePkg
to define EDKII_PEI_MP_SERVICES2_PPI_GUID and
EDKII_PEI_MP_SERVICES2_PPI.
All references to the EDK II PEI MP Services 2 PPI can be
removed after all downstream consumers have had a chance
to perform the migration.
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>