drm/omap: convert dss_mgr_unregister_framedone_handler to accept omap_channel

We are removing uses of 'struct omap_overlay_manager'. This patch
changes dss_mgr_unregister_framedone_handler() to accept 'enum
omap_channel' instead of 'struct omap_overlay_manager'.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
index ae9cae3..186d978 100644
--- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
+++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
@@ -95,7 +95,7 @@
 void dss_mgr_start_update(enum omap_channel channel);
 int dss_mgr_register_framedone_handler(enum omap_channel channel,
 		void (*handler)(void *), void *data);
-void dss_mgr_unregister_framedone_handler(struct omap_overlay_manager *mgr,
+void dss_mgr_unregister_framedone_handler(enum omap_channel channel,
 		void (*handler)(void *), void *data);
 
 #endif /* __OMAP_DRM_DSS_H */