Add comments for most of enum data type.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@6924 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Include/Protocol/Cpu.h

@@ -24,6 +24,9 @@
 
 typedef struct _EFI_CPU_ARCH_PROTOCOL   EFI_CPU_ARCH_PROTOCOL;
 
+///
+/// The type of flush operation
+///
 typedef enum {
   EfiCpuFlushTypeWriteBackInvalidate,
   EfiCpuFlushTypeWriteBack,
@@ -31,6 +34,9 @@ typedef enum {
   EfiCpuMaxFlushType
 } EFI_CPU_FLUSH_TYPE;
 
+///
+/// The type of processor INIT.
+///
 typedef enum {
   EfiCpuInit,
   EfiCpuMaxInitType