Clear caches during init

Some processor families leave residue in the processor cache
after SMM initialization phase.  Especially, when processors are
initializing SMM in parallel.  This residue sometimes results in
apparent inconsistency in shared tables.

Signed-off-by: Eugene Myers <edmyers@tycho.nsa.gov>

Stm/StmPkg/Core/Init/StmInit.c

@@ -1020,7 +1020,9 @@ ApInit (
 {
   X86_REGISTER        *Reg;
   IA32_DESCRIPTOR IdtrLoad;
-
+  // Make sure there is no residue
+  AsmWbinvd();  // make sure it gets out
+
   while (!mIsBspInitialized) {
     //
     // Wait here