UefiCpuPkg/MpInitLib: Add MP Initialize library class definition

UefiCpuPkg/MpInitLib: Add MP Initialize library class definition

MP Initialize library provides basic functionalities to do APs initialization,
to manage MP information and to wakeup APs to execute AP task.

It could be consumed by CPU MP PEI or DXE drivers to provide CPU MP PPI/Protocol
services.

v4:
  1. MpInitLibGetProcessorInfo():
     Update HealthData type from UINT32 to EFI_HEALTH_FLAGS.
     Add #include <Ppi/SecPlatformInformation.h>
  2. MpInitLibSwitchBSP():
     Return EFI_DEVICE_ERROR instead of EFI_SUCCESS if the calling processor is
     an AP.
  3. MpInitLibStartupThisAP():
     Fix several incorrect references to "APs" to match PI spec.
  4. MpInitLibSwitchBSP() and MpInitLibEnableDisableAP():
     Fix incorrect description on ProcessorNumber.
  5. Trim whitespace at end of line.

v3:
  1. Add whitespace after MpInitLibInitialize
  2. Rename MpInitLibSwitchBsp to MpInitLibSwitchBSP to match PI spec

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