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/arch/mips/mach-ath79/ar934x/cpu.c

@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2016 Marek Vasut <marex@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+
+/* The lowlevel_init() is not needed on AR934x */
+void lowlevel_init(void) {}