MdeModulePkg/VariableRuntimeDxe: factor out boot service accesses

In preparation of providing a standalone MM based variable runtime
driver, move the existing SMM driver to the new MM services table,
and factor out some pieces that are specific to the traditional
driver, mainly related to the use of UEFI boot services, which are
not accessible to standalone MM drivers.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>

MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c

@@ -21,7 +21,6 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Library/DebugLib.h>
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
-#include <Library/UefiBootServicesTableLib.h>
 #include "Variable.h"
 
 typedef struct {
@@ -419,8 +418,6 @@ MorLockInitAtEndOfDxe (
 {
   UINTN      MorSize;
   EFI_STATUS MorStatus;
-  EFI_STATUS TcgStatus;
-  VOID       *TcgInterface;
 
   if (!mMorLockInitializationRequired) {
     //
@@ -458,20 +455,7 @@ MorLockInitAtEndOfDxe (
     // can be deduced from the absence of the TCG / TCG2 protocols, as edk2's
     // MOR implementation depends on (one of) those protocols.
     //
-    TcgStatus = gBS->LocateProtocol (
-                       &gEfiTcg2ProtocolGuid,
-                       NULL,                     // Registration
-                       &TcgInterface
-                       );
-    if (EFI_ERROR (TcgStatus)) {
-      TcgStatus = gBS->LocateProtocol (
-                         &gEfiTcgProtocolGuid,
-                         NULL,                   // Registration
-                         &TcgInterface
-                         );
-    }
-
-    if (!EFI_ERROR (TcgStatus)) {
+    if (VariableHaveTcgProtocols ()) {
       //
       // The MOR variable originates from the platform firmware; set the MOR
       // Control Lock variable to report the locking capability to the OS.