drm/omap: omap_display_timings: Use display_flags for sync edge

In preparation to move the stack to use the generic videmode struct for
display timing information use display_flags for sync edge.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c b/drivers/gpu/drm/omapdrm/omap_connector.c
index 5fa15da..562a04d 100644
--- a/drivers/gpu/drm/omapdrm/omap_connector.c
+++ b/drivers/gpu/drm/omapdrm/omap_connector.c
@@ -107,8 +107,9 @@ void copy_timings_drm_to_omap(struct omap_video_timings *timings,
 	else
 		timings->flags |= DISPLAY_FLAGS_VSYNC_LOW;
 
-	timings->flags |= DISPLAY_FLAGS_DE_HIGH | DISPLAY_FLAGS_PIXDATA_POSEDGE;
-	timings->sync_pclk_edge = OMAPDSS_DRIVE_SIG_FALLING_EDGE;
+	timings->flags |= DISPLAY_FLAGS_DE_HIGH |
+			  DISPLAY_FLAGS_PIXDATA_POSEDGE |
+			  DISPLAY_FLAGS_SYNC_NEGEDGE;
 }
 
 static enum drm_connector_status omap_connector_detect(