MdeModulePkg: Change OPTIONAL keyword usage style

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3760

Update all use of ', OPTIONAL' to ' OPTIONAL,' for function params.

Cc: Andrew Fish <afish@apple.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

MdeModulePkg/Core/PiSmmCore/Dispatcher.c

@@ -1248,8 +1248,8 @@ EFI_STATUS
 EFIAPI
 SmmDriverDispatchHandler (
   IN     EFI_HANDLE  DispatchHandle,
-  IN     CONST VOID  *Context,        OPTIONAL
-  IN OUT VOID        *CommBuffer,     OPTIONAL
+  IN     CONST VOID  *Context         OPTIONAL,
+  IN OUT VOID        *CommBuffer      OPTIONAL,
   IN OUT UINTN       *CommBufferSize  OPTIONAL
   )
 {