OvmfPkg: set gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection to FALSE

OvmfPkg: set gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection to FALSE

Explanation from Michael Kinney:

  This PCD allows a platform to provide PlatformSmmBspElection() in a
  platform specific SmmCpuPlatformHookLib instance to decide which CPU
  gets elected to be the BSP in each SMI.

  The SmmCpuPlatformHookLibNull [instance] always returns EFI_NOT_READY
  for that function, which makes the module behave the same as the PCD
  being set to FALSE.

  The default is TRUE, so the platform lib is always called, so a platform
  developer can implement the hook function and does not have to also
  change a PCD setting for the hook function to be active.

  A platform that wants to eliminate the call to the hook function
  [altogether] can set the PCD to FALSE.

  So for OVMF, I think it makes sense to set this PCD to FALSE in the DSC
  file.

Suggested-by: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19053 6f19259b-4bc3-4df7-8a09-765794883524