link: move fallback definitions of AT_* constants to xlat/

* link.c: Move definitions of AT_* constants ...
* xlat/at_flags.in: ... here.
diff --git a/link.c b/link.c
index 74ff514..b2bb222 100644
--- a/link.c
+++ b/link.c
@@ -2,22 +2,6 @@
 
 #include <fcntl.h>
 
-#ifndef AT_SYMLINK_NOFOLLOW
-# define AT_SYMLINK_NOFOLLOW	0x100
-#endif
-#ifndef AT_REMOVEDIR
-# define AT_REMOVEDIR		0x200
-#endif
-#ifndef AT_SYMLINK_FOLLOW
-# define AT_SYMLINK_FOLLOW	0x400
-#endif
-#ifndef AT_NO_AUTOMOUNT
-# define AT_NO_AUTOMOUNT	0x800
-#endif
-#ifndef AT_EMPTY_PATH
-# define AT_EMPTY_PATH		0x1000
-#endif
-
 #include "xlat/at_flags.h"
 
 SYS_FUNC(link)
diff --git a/xlat/at_flags.in b/xlat/at_flags.in
index 1a790d5..77a8de9 100644
--- a/xlat/at_flags.in
+++ b/xlat/at_flags.in
@@ -1,5 +1,5 @@
-AT_SYMLINK_NOFOLLOW
-AT_REMOVEDIR
-AT_SYMLINK_FOLLOW
-AT_NO_AUTOMOUNT
-AT_EMPTY_PATH
+AT_SYMLINK_NOFOLLOW	0x100
+AT_REMOVEDIR		0x200
+AT_SYMLINK_FOLLOW	0x400
+AT_NO_AUTOMOUNT		0x800
+AT_EMPTY_PATH		0x1000