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/Universal/RegularExpressionDxe/RegularExpressionDxe.h

@@ -76,9 +76,9 @@ RegularExpressionMatch (
   IN  EFI_REGULAR_EXPRESSION_PROTOCOL *This,
   IN  CHAR16                          *String,
   IN  CHAR16                          *Pattern,
-  IN  EFI_REGEX_SYNTAX_TYPE           *SyntaxType, OPTIONAL
+  IN  EFI_REGEX_SYNTAX_TYPE           *SyntaxType  OPTIONAL,
   OUT BOOLEAN                         *Result,
-  OUT EFI_REGEX_CAPTURE               **Captures, OPTIONAL
+  OUT EFI_REGEX_CAPTURE               **Captures  OPTIONAL,
   OUT UINTN                           *CapturesCount
   );