kirkwood: fix calls to kirkwood_mpp_conf

With the new second save argument introduced by the previous patch, all
the calls to the function had to be fixed.

Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Holger Brunck <holger.brunck@keymile.com>
cc: Prafulla Wadaskar <prafulla@marvell.com>
diff --git a/board/Seagate/dockstar/dockstar.c b/board/Seagate/dockstar/dockstar.c
index 38473e5..fc88520 100644
--- a/board/Seagate/dockstar/dockstar.c
+++ b/board/Seagate/dockstar/dockstar.c
@@ -100,7 +100,7 @@
 		MPP49_GPIO,
 		0
 	};
-	kirkwood_mpp_conf(kwmpp_config);
+	kirkwood_mpp_conf(kwmpp_config, NULL);
 	return 0;
 }