OMAP: DSS2: move wait_vsync()

Move wait_vsync() from omap_dss_device to overlay manager.

This is part of a larger patch-set, which moves the control from omapdss
driver to the display driver.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
diff --git a/arch/arm/plat-omap/include/plat/display.h b/arch/arm/plat-omap/include/plat/display.h
index 9291aa1..059b35c 100644
--- a/arch/arm/plat-omap/include/plat/display.h
+++ b/arch/arm/plat-omap/include/plat/display.h
@@ -370,6 +370,7 @@
 
 	int (*apply)(struct omap_overlay_manager *mgr);
 	int (*wait_for_go)(struct omap_overlay_manager *mgr);
+	int (*wait_for_vsync)(struct omap_overlay_manager *mgr);
 };
 
 struct omap_dss_device {
@@ -479,7 +480,6 @@
 	int (*update)(struct omap_dss_device *dssdev,
 			       u16 x, u16 y, u16 w, u16 h);
 	int (*sync)(struct omap_dss_device *dssdev);
-	int (*wait_vsync)(struct omap_dss_device *dssdev);
 
 	int (*set_update_mode)(struct omap_dss_device *dssdev,
 			enum omap_dss_update_mode);