xkb: move include guards up to wrap the whole file

See: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
Signed-off-by: Mike Gelfand <mikedld@mikedld.com>

xkb/xkbDflts.h

@@ -1,12 +1,13 @@
 /* This file generated automatically by xkbcomp */
 /* DO  NOT EDIT */
-#ifdef HAVE_DIX_CONFIG_H
-#include <dix-config.h>
-#endif
 
 #ifndef DEFAULT_H
 #define DEFAULT_H 1
 
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
 #define GET_ATOM(d,s)	MakeAtom(s,strlen(s),1)
 #define DPYTYPE	char *
 #define NUM_KEYS	1