OMAPDSS: DISPC: make dispc_ovl_set_channel_out() public

Make dispc_ovl_set_channel_out() public so that later patches can handle
changing overlay's manager.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index 7d2b6dd..f899f0f 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -402,6 +402,8 @@
 		bool ilace, enum omap_channel channel, bool replication,
 		u32 fifo_low, u32 fifo_high);
 int dispc_ovl_enable(enum omap_plane plane, bool enable);
+void dispc_ovl_set_channel_out(enum omap_plane plane,
+		enum omap_channel channel);
 
 
 void dispc_mgr_enable_fifohandcheck(enum omap_channel channel, bool enable);