drm/imx: ipuv3-plane: fix planar YUV 4:2:0 support

The driver already advertises multi-planar YUV support, but
previously the U/V offset and stride setup was missing.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/gpu/drm/imx/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3-plane.c
index 70455d2..79df184 100644
--- a/drivers/gpu/drm/imx/ipuv3-plane.c
+++ b/drivers/gpu/drm/imx/ipuv3-plane.c
@@ -312,6 +312,18 @@
 	if (interlaced)
 		ipu_cpmem_interlaced_scan(ipu_plane->ipu_ch, fb->pitches[0]);
 
+	if (fb->pixel_format == DRM_FORMAT_YUV420) {
+		ipu_cpmem_set_yuv_planar_full(ipu_plane->ipu_ch,
+					      ipu_plane->stride[1],
+					      ipu_plane->u_offset,
+					      ipu_plane->v_offset);
+	} else if (fb->pixel_format == DRM_FORMAT_YVU420) {
+		ipu_cpmem_set_yuv_planar_full(ipu_plane->ipu_ch,
+					      ipu_plane->stride[1],
+					      ipu_plane->v_offset,
+					      ipu_plane->u_offset);
+	}
+
 	ipu_plane->w = src_w;
 	ipu_plane->h = src_h;