[media] v4l: vsp1: uds: Enable scaling of alpha layer

Scaling of the alpha layer is disabled as both the RPF and WPF are
configured to hardcode the alpha value to 255. This results in a 0 alpha
value at the UDS output, making the image invisible when alpha blended
in the BRU. Fix it by enabling scaling of the alpha layer.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/platform/vsp1/vsp1_uds.c

@@ -131,7 +131,7 @@ static int uds_s_stream(struct v4l2_subdev *subdev, int enable)
 		return 0;
 
 	/* Enable multi-tap scaling. */
-	vsp1_uds_write(uds, VI6_UDS_CTRL, VI6_UDS_CTRL_BC);
+	vsp1_uds_write(uds, VI6_UDS_CTRL, VI6_UDS_CTRL_AON | VI6_UDS_CTRL_BC);
 
 	vsp1_uds_write(uds, VI6_UDS_PASS_BWIDTH,
 		       (uds_passband_width(uds->hscale)
@@ -139,7 +139,6 @@ static int uds_s_stream(struct v4l2_subdev *subdev, int enable)
 		       (uds_passband_width(uds->vscale)
 				<< VI6_UDS_PASS_BWIDTH_V_SHIFT));
 
-
 	/* Set the scaling ratios and the output size. */
 	format = &uds->entity.formats[UDS_PAD_SOURCE];