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/arm/cpu/armv7/bcm235xx/Makefile

@@ -0,0 +1,12 @@
+#
+# Copyright 2013 Broadcom Corporation.
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-y	+= clk-core.o
+obj-y	+= clk-bcm235xx.o
+obj-y	+= clk-sdio.o
+obj-y	+= clk-bsc.o
+obj-$(CONFIG_BCM_SF2_ETH) += clk-eth.o
+obj-y	+= clk-usb-otg.o