OvmfPkg: 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: Andrew Fish <afish@apple.com>

OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.c

@@ -278,7 +278,7 @@ Tpm2CommandChangeEps (
 STATIC
 UINT32
 Tcg2ExecutePhysicalPresence (
-  IN      TPM2B_AUTH                       *PlatformAuth,  OPTIONAL
+  IN      TPM2B_AUTH                       *PlatformAuth   OPTIONAL,
   IN      UINT32                           CommandCode,
   IN      UINT32                           CommandParameter
   )