drm/imx: enable IDMAC watermark feature

The DMFC is configured to supply a watermark signal that can be used to
temporarily increase channel priority if the FIFO runs low. Use it.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/imx/ipuv3-plane.c

@@ -638,6 +638,7 @@ static void ipu_plane_atomic_update(struct drm_plane *plane,
 	ipu_cpmem_set_fmt(ipu_plane->ipu_ch, fb->format->format);
 	ipu_cpmem_set_burstsize(ipu_plane->ipu_ch, burstsize);
 	ipu_cpmem_set_high_priority(ipu_plane->ipu_ch);
+	ipu_idmac_enable_watermark(ipu_plane->ipu_ch, true);
 	ipu_idmac_set_double_buffer(ipu_plane->ipu_ch, 1);
 	ipu_cpmem_set_stride(ipu_plane->ipu_ch, fb->pitches[0]);
 	ipu_cpmem_set_axi_id(ipu_plane->ipu_ch, axi_id);