UefiCpuPkg/PiSmmCpuDxeSmm: Check SMM Debug Agent support or not

This patch is to check SMM Debug Agent support or not before
InitializeDebugAgent.

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

UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c

@@ -837,7 +837,9 @@ SmmRestoreCpu (
     //
     // Initialize Debug Agent to support source level debug
     //
-    InitializeDebugAgent (DEBUG_AGENT_INIT_THUNK_PEI_IA32TOX64, (VOID *)&Ia32Idtr, NULL);
+    if (mSmmDebugAgentSupport) {
+      InitializeDebugAgent (DEBUG_AGENT_INIT_THUNK_PEI_IA32TOX64, (VOID *)&Ia32Idtr, NULL);
+    }
   }
 
   mBspApicId = GetApicId ();