Revert "Unmark GstDebugColorFlags as flags"

This reverts commit 4eb9211e1a297f75c3f28067c893053ba51ba3db.

Change-Id: I353922f0d96bf2050791d6ee167397c43464ecde
diff --git a/gst/gstinfo.h b/gst/gstinfo.h
index e4aa13a..82e4f9b 100644
--- a/gst/gstinfo.h
+++ b/gst/gstinfo.h
@@ -151,7 +151,7 @@
  * These are some terminal style flags you can use when creating your
  * debugging categories to make them stand out in debugging output.
  */
-typedef enum {
+typedef enum { /*< flags >*/
   /* colors */
   GST_DEBUG_FG_BLACK		= 0x0000,
   GST_DEBUG_FG_RED		= 0x0001,