UefiCpuPkg/MpInitLib: Avoid call PcdGet* in Ap & Bsp.

UefiCpuPkg/MpInitLib: Avoid call PcdGet* in Ap & Bsp.

MicrocodeDetect function will run by every threads, and it will
use PcdGet to get PcdCpuMicrocodePatchAddress and
PcdCpuMicrocodePatchRegionSize, if change both PCD default to dynamic,
system will in non-deterministic behavior.

By design, UEFI/PI services are single threaded and not re-entrant
so Multi processor code should not use UEFI/PI services. Here, Pcd
protocol/PPI is used to access dynamic PCDs so it would result in
non-deterministic behavior.

This code get PCD value in BSP and save them in CPU_MP_DATA for Ap.

https://bugzilla.tianocore.org/show_bug.cgi?id=726

Cc: Crystal Lee <CrystalLee@ami.com.tw>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>