nfs41: add mount command option minorversion

mount -t nfs4 -o minorversion=[0|1] specifies whether to use 4.0 or 4.1.
By default, the minorversion is set to 0.

Signed-off-by: Mike Sager <sager@netapp.com>
[set default minorversion to 0 as per Trond and SteveD's request]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index e4d6a83..ffa6bd5 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -44,6 +44,7 @@
 	unsigned int		auth_flavor_len;
 	rpc_authflavor_t	auth_flavors[1];
 	char			*client_address;
+	unsigned int		minorversion;
 	char			*fscache_uniq;
 
 	struct {