UefiCpuPkg: 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: Ray Ni <ray.ni@intel.com>

UefiCpuPkg/Library/MtrrLib/MtrrLib.c

@@ -1287,8 +1287,8 @@ MtrrLibCalculateSubtractivePath (
   IN UINT16                      Stop,
   IN UINT8                       Types,
   IN UINT8                       TypeCount,
-  IN OUT MTRR_MEMORY_RANGE       *Mtrrs,       OPTIONAL
-  IN UINT32                      MtrrCapacity, OPTIONAL
+  IN OUT MTRR_MEMORY_RANGE       *Mtrrs        OPTIONAL,
+  IN UINT32                      MtrrCapacity  OPTIONAL,
   IN OUT UINT32                  *MtrrCount    OPTIONAL
   )
 {