NFS: Update NFS4_BITMAP_SIZE

v4.1/v4.2 have define attributes at word2, nfs client also support
security label now.

v3, same as v2.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

include/uapi/linux/nfs4.h

@@ -15,7 +15,7 @@
 
 #include <linux/types.h>
 
-#define NFS4_BITMAP_SIZE	2
+#define NFS4_BITMAP_SIZE	3
 #define NFS4_VERIFIER_SIZE	8
 #define NFS4_STATEID_SEQID_SIZE 4
 #define NFS4_STATEID_OTHER_SIZE 12