NFS: Move nfs_idmap.h into fs/nfs/

This file is only used internally to the NFS v4 module, so it doesn't
need to be in the global include path.  I also renamed it from
nfs_idmap.h to nfs4idmap.h to emphasize that it's an NFSv4-only include
file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index a26880c..0aea978 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -52,10 +52,10 @@
 #include <linux/nfs.h>
 #include <linux/nfs4.h>
 #include <linux/nfs_fs.h>
-#include <linux/nfs_idmap.h>
 
 #include "nfs4_fs.h"
 #include "internal.h"
+#include "nfs4idmap.h"
 #include "nfs4session.h"
 #include "pnfs.h"
 #include "netns.h"