drm/rockchip: dw-mipi-dsi: include bad value in error message

As an aid to debugging.
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170224125506.21533-8-john@metanate.com

drivers/gpu/drm/rockchip/dw-mipi-dsi.c

@@ -646,7 +646,8 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
 		ret = dw_mipi_dsi_dcs_long_write(dsi, msg);
 		break;
 	default:
-		dev_err(dsi->dev, "unsupported message type\n");
+		dev_err(dsi->dev, "unsupported message type 0x%02x\n",
+			msg->type);
 		ret = -EINVAL;
 	}