Add the Xilinx Bootgen as bintool. Xilinx Bootgen is used to create
bootable SPL (FSBL in Xilinx terms) images for Zynq/ZynqMP devices. The
btool creates a signed version of the SPL. Additionally to signing the
key source for the decryption engine can be passend to the boot image.
Signed-off-by: Lukas Funke <lukas.funke@weidmueller.com>
Add documentation for btool which calls 'fdt_add_pubkey'
Signed-off-by: Lukas Funke <lukas.funke@weidmueller.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
