UefiCpuPkg: Update DEC/DSC files for new includes and libraries

UefiCpuPkg: Update DEC/DSC files for new includes and libraries

Add SmmCpuPlatformHookLib library class declaration
Add SmmCpuFeaturesLib library class declaration
Add gEfiSmmCpuServiceProtocolGuid protocol declaration
Build SmmCpuPlatformHookLibNull library instance
Build SmmCpuFeaturesLib library instance

Changes between [PATCH v1] and [PATCH v2]:
1) Use module type specific CpuExceptionHandlerLib in DSC file
   instead of Null library instance

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18644 6f19259b-4bc3-4df7-8a09-765794883524