NFS: Alias the nfs module to nfs4

commit 425e776d93a7a5070b77d4f458a5bab0f924652c upstream.

This allows distros to remove the line from their modprobe
configuration.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>