libceph: move feature bits to separate header

This is simply cleanup that will keep things more closely synced with the
userland code.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

fs/ceph/mds_client.c

@@ -10,6 +10,7 @@
 #include "super.h"
 #include "mds_client.h"
 
+#include <linux/ceph/ceph_features.h>
 #include <linux/ceph/messenger.h>
 #include <linux/ceph/decode.h>
 #include <linux/ceph/pagelist.h>