UefiCpuPkg/CpuMpPei: Add GetApLoopMode() to get AP loop mode

UefiCpuPkg/CpuMpPei: Add GetApLoopMode() to get AP loop mode

Add GetApLoopMode() that will get PCD PcdCpuApLoopMode firstly. If it is
ApInMwaitLoop, we will check if MONITOR/MWAIT feature supported by CPUID. If
MONITOR/MWAIT feature is not supported, force AP loop mode to ApInHltLoop.

GetApLoopMode() also return the largest line size required.

Contributed-under: TianoCore Contribution Agreement 1.0
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Tested-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19343 6f19259b-4bc3-4df7-8a09-765794883524