[media] v4l: vsp1: Fix tri-planar format support through DRM API

The vsp1 driver supports tri-planar formats, but the DRM API only passes
two memory addresses. Add a third one.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/include/media/vsp1.h b/include/media/vsp1.h
index 9322d977..458b400 100644
--- a/include/media/vsp1.h
+++ b/include/media/vsp1.h
@@ -26,7 +26,7 @@
 struct vsp1_du_atomic_config {
 	u32 pixelformat;
 	unsigned int pitch;
-	dma_addr_t mem[2];
+	dma_addr_t mem[3];
 	struct v4l2_rect src;
 	struct v4l2_rect dst;
 	unsigned int alpha;