MdeModulePkg/SecurityStubDxe: Mark the File parameter as OPTIONAL

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2652

According to the description, the File is optional and can be NULL

Signed-off-by: Guomin Jiang <guomin.jiang@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Liming Gao <liming.gao@intel.com>

Reviewed-by: Jian J Wang <jian.j.wang@intel.com>

MdeModulePkg/Universal/SecurityStubDxe/SecurityStub.c

@@ -129,7 +129,7 @@ EFI_STATUS
 EFIAPI
 Security2StubAuthenticate (
   IN CONST EFI_SECURITY2_ARCH_PROTOCOL *This,
-  IN CONST EFI_DEVICE_PATH_PROTOCOL    *File,
+  IN CONST EFI_DEVICE_PATH_PROTOCOL    *File, OPTIONAL
   IN VOID                              *FileBuffer,
   IN UINTN                             FileSize,
   IN BOOLEAN                           BootPolicy