sunxi: Fix display timing flags

flags member of struct timing was not initialized,
this took to unpredictable behaviour of display flags,
such DISPLAY_FLAGS_HSYNC_HIGH instead of _LOW etc.

Init timing->flags = 0

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

drivers/video/sunxi/sunxi_display.c

@@ -625,6 +625,8 @@ static void sunxi_ctfb_mode_to_display_timing(const struct ctfb_res_modes *mode,
 	timing->vback_porch.typ = mode->upper_margin;
 	timing->vsync_len.typ = mode->vsync_len;
 
+	timing->flags = 0;
+
 	if (mode->sync & FB_SYNC_HOR_HIGH_ACT)
 		timing->flags |= DISPLAY_FLAGS_HSYNC_HIGH;
 	else