NFS: Remake nfsroot_mount as a permanent part of NFS client

In preparation for supporting NFSv2 and NFSv3 mount option handling in the
kernel NFS client, convert mount_clnt.c to be a permanent part of the NFS
client, instead of built only when CONFIG_ROOT_NFS is enabled.

In addition, we also replace the "struct sockaddr_in *" argument with
something more generic, to help support IPv6 at some later point.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 04f659f..c098ae1 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -494,10 +494,9 @@
 
 /*
  * linux/fs/mount_clnt.c
- * (Used only by nfsroot module)
  */
-extern int  nfsroot_mount(struct sockaddr_in *, char *, struct nfs_fh *,
-		int, int);
+extern int  nfs_mount(struct sockaddr *, size_t, char *, char *,
+		      int, int, struct nfs_fh *);
 
 /*
  * inline functions