UefiCpuPkg: Add SmmRelocationLib class

Intel plans to separate the smbase relocation logic from
PiSmmCpuDxeSmm driver, and the related behavior will be
moved to the new interface defined by the SmmRelocationLib
class.

The SmmRelocationLib class provides the SmmRelocationInit()
interface for platform to do the smbase relocation, which
shall provide below 2 functionalities:
1. Relocate smbases for each processor.
2. Create the gSmmBaseHobGuid HOB.

With SmmRelocationLib, PiSmmCpuDxeSmm driver (which runs at
a later phase) shall:
1. Consume the gSmmBaseHobGuid HOB for the relocated smbases
for each Processor.
2. Execute the early SMM Init.

This patch just provides the SmmRelocationLib class.

Cc: Ray Ni <ray.ni@intel.com>
Cc: Zeng Star <star.zeng@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

UefiCpuPkg/UefiCpuPkg.dec

@@ -71,6 +71,9 @@
   ## @libraryclass   Provides functions for SMM CPU Sync Operation.
   SmmCpuSyncLib|Include/Library/SmmCpuSyncLib.h
 
+  ## @libraryclass   Provides functions for SMM Relocation Operation.
+  SmmRelocationLib|Include/Library/SmmRelocationLib.h
+
 [LibraryClasses.RISCV64]
   ##  @libraryclass  Provides functions to manage MMU features on RISCV64 CPUs.
   ##