MdeModulePkg: Change TCG MOR variables to use VariablePolicy

https://bugzilla.tianocore.org/show_bug.cgi?id=2522

These were previously using VarLock, which is
being deprecated.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Bret Barkelew <brbarkel@microsoft.com>
Signed-off-by: Bret Barkelew <brbarkel@microsoft.com>
Reviewed-by: Dandan Bi <dandan.bi@intel.com>
Acked-by: Jian J Wang <jian.j.wang@intel.com>

MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf

@@ -76,6 +76,7 @@
   SynchronizationLib
   VarCheckLib
   VariablePolicyLib
+  VariablePolicyHelperLib
 
 [Protocols]
   gEfiSmmFirmwareVolumeBlockProtocolGuid        ## CONSUMES