Add SMB2.02 dialect support

This patch enables optional for original SMB2 (SMB2.02) dialect
by specifying vers=2.0 on mount.

Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index d1a93d3..ac66409 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -178,6 +178,7 @@
 
 enum smb_version {
 	Smb_1 = 1,
+	Smb_20,
 	Smb_21,
 	Smb_30,
 };