drm: xlnx: dp: Reset DisplayPort IP

Assert DisplayPort reset signal before deasserting,
it is to clear out any registers programmed before booting kernel.
Signed-off-by: Rohit Visavalia <rohit.visavalia@amd.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240216124043.1226713-1-rohit.visavalia@amd.com

drivers/gpu/drm/xlnx/zynqmp_dp.c

@@ -1714,6 +1714,10 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub)
 		goto err_free;
 	}
 
+	ret = zynqmp_dp_reset(dp, true);
+	if (ret < 0)
+		return ret;
+
 	ret = zynqmp_dp_reset(dp, false);
 	if (ret < 0)
 		goto err_free;