tools: zynqmpimage: Add bif support

tools: zynqmpimage: Add bif support

The officially described way to generate boot.bin files for ZynqMP is to
describe the contents of the target binary using a file of the "bif"
format.  This file then links to other files that all get packed into a
bootable image.

This patch adds support to read such a .bif file and generate a respective
ZynqMP boot.bin file that can include the normal image and pmu files, but
also supports image partitions now. This makes it a handy replacement for
the proprietary "bootgen" utility that is currently used to generate
boot.bin files with FSBL.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>