[Doxygen] fix not recognizing typedef enum

Author: cindytsai

doc/Doxyfile

@@ -470,7 +470,7 @@ INLINE_SIMPLE_STRUCTS  = NO
 # types are typedef'ed and only the typedef is referenced, never the tag name.
 # The default value is: NO.
 
-TYPEDEF_HIDES_STRUCT   = NO
+TYPEDEF_HIDES_STRUCT   = YES
 
 # The size of the symbol lookup cache can be set using LOOKUP_CACHE_SIZE. This
 # cache is used to resolve symbols given their name and scope. Since this can be