fdo#82577: Handle Icon

It appears that this became unnecessary at some point

Change-Id: I6638d68d1c44162b4aa62224dc03c19c2413180e
Reviewed-on: https://gerrit.libreoffice.org/11715Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>

include/postx.h

@@ -24,9 +24,6 @@
 }
 #endif
 
-/* X Types */
-#undef Icon
-
 #undef Min
 #undef Max
 #undef DestroyAll

include/prex.h

@@ -24,11 +24,6 @@
 #error No X headers should be included for MACOSX even if they are present in the SDK
 #endif
 
-/* Types from <X11/X.h> that clash with LO's identifiers
- * and we don't need.
- */
-#define Icon        HIDE_XLIB_Icon
-
 #if defined __cplusplus
 extern "C" {
 #endif