UefiCpuPkg: Add SmmCpuPlatformHookLib

Add SmmCpuPlatformHookLib that provides platform specific functions
that are used to initialize SMM and process SMIs.  A Null instance
of this library is provided that should work for most platforms.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18639 6f19259b-4bc3-4df7-8a09-765794883524