UefiCpuPkg/RegisterCpuFeaturesLib: Avoid AP calls PeiService.

UefiCpuPkg/RegisterCpuFeaturesLib: Avoid AP calls PeiService.

V3:
   Define union to specify the ppi or protocol.

V2:
1. Initialize CpuFeaturesData->MpService in CpuInitDataInitialize
   and make this function been called at the begin of the
   initialization.
2. let all other functions use CpuFeaturesData->MpService install
   of locate the protocol itself.

V1:
GetProcessorIndex function calls GetMpPpi to get the MP Ppi.
Ap will calls GetProcessorIndex function which final let AP calls
PeiService.

This patch avoid GetProcessorIndex call PeiService.

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1411

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>