MdePkg: 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>

MdePkg/Library/BasePrintLib/PrintLibInternal.c

@@ -532,7 +532,7 @@ BasePrintLibSPrintMarker (
   IN  UINTN        BufferSize,
   IN  UINTN        Flags,
   IN  CONST CHAR8  *Format,
-  IN  VA_LIST      VaListMarker,   OPTIONAL
+  IN  VA_LIST      VaListMarker    OPTIONAL,
   IN  BASE_LIST    BaseListMarker  OPTIONAL
   )
 {

MdePkg/Library/BasePrintLib/PrintLibInternal.h

@@ -82,7 +82,7 @@ BasePrintLibSPrintMarker (
   IN  UINTN        BufferSize,
   IN  UINTN        Flags,
   IN  CONST CHAR8  *Format,
-  IN  VA_LIST      VaListMarker,   OPTIONAL
+  IN  VA_LIST      VaListMarker    OPTIONAL,
   IN  BASE_LIST    BaseListMarker  OPTIONAL
   );