UefiCpuPkg/PiSmmCpuDxeSmm: Fix invalid InitializeMpSyncData call

UefiCpuPkg/PiSmmCpuDxeSmm: Fix invalid InitializeMpSyncData call

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4338

No need call InitializeMpSyncData during normal boot SMI init,
because mSmmMpSyncData is NULL at that time. mSmmMpSyncData is
allocated in InitializeMpServiceData, which is invoked after
normal boot SMI init (SmmRelocateBases).

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Zeng Star <star.zeng@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ray Ni <ray.ni@Intel.com>