OMAPDSS: pass ovl manager to dss_start_update

dss_start_update() takes currently the dss device as a parameter. Change
the parameter to ovl manager, as that is what the dss_start_update()
actually needs. Change the name of the function to
dss_mgr_start_update() to reflect the change.

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 7f6a612..39d4837 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -182,7 +182,7 @@
 int dss_init_overlay_managers(struct platform_device *pdev);
 void dss_uninit_overlay_managers(struct platform_device *pdev);
 int dss_mgr_wait_for_go_ovl(struct omap_overlay *ovl);
-void dss_start_update(struct omap_dss_device *dssdev);
+void dss_mgr_start_update(struct omap_overlay_manager *mgr);
 
 /* overlay */
 void dss_init_overlays(struct platform_device *pdev);