MdePkg: Fix a comment typo in Include/Ppi/MpServices.h

The summary of EFI_PEI_MP_SERVICES_WHOAMI is modified to show the correct
description of this service.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17984 6f19259b-4bc3-4df7-8a09-765794883524
1 file changed