UefiCpuPkg: SmmCpuExceptionHandlerLib: Added StandaloneMm module support

UefiCpuPkg: SmmCpuExceptionHandlerLib: Added StandaloneMm module support

This change of SmmCpuExceptionHandlerLib adds support for StandaloneMm
components to allow x64 StandaloneMm environment setting up exception
handlers.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Kun Qin <kun.q@outlook.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>