UefiCpuPkg/PiSmmCpuDxeSmm: Allocate buffer for MSRs semaphores

UefiCpuPkg/PiSmmCpuDxeSmm: Allocate buffer for MSRs semaphores

Allocate MSRs semaphores in allocated aligned semaphores buffer.
And add it into semaphores structure.

Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>