avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/drivers/video/backlight-uclass.c

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <backlight.h>
+
+int backlight_enable(struct udevice *dev)
+{
+	const struct backlight_ops *ops = backlight_get_ops(dev);
+
+	if (!ops->enable)
+		return -ENOSYS;
+
+	return ops->enable(dev);
+}
+
+UCLASS_DRIVER(backlight) = {
+	.id		= UCLASS_PANEL_BACKLIGHT,
+	.name		= "backlight",
+};