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/post/cpu/ppc4xx/Makefile

@@ -0,0 +1,16 @@
+#
+# (C) Copyright 2002-2007
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-y += cache_4xx.o
+obj-y += cache.o
+obj-y += denali_ecc.o
+obj-y += ether.o
+obj-y += fpu.o
+obj-y += ocm.o
+obj-y += spr.o
+obj-y += uart.o
+obj-y += watchdog.o