UefiCpuPkg/MpInitLib: Collect processors' CPUID & Platform ID info

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2429

This commit will collect the CPUID and Platform ID information for each
processor within system. They will be stored in the CPU_AP_DATA structure.

These information will be used in the next commit to decide whether a
microcode patch will be loaded into memory.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Signed-off-by: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>

UefiCpuPkg/Library/MpInitLib/MpLib.h

@@ -122,6 +122,8 @@ typedef struct {
   UINT64                         CurrentTime;
   UINT64                         TotalTime;
   EFI_EVENT                      WaitEvent;
+  UINT32                         ProcessorSignature;
+  UINT8                          PlatformId;
 } CPU_AP_DATA;
 
 //