Create example banked fw boot disk images

To help with fwu testing, this change adds two UEFI format firmware
image files with the partitions expected in a typical boot image
that supports A/B updates. See readme.md for details.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I14515be199edab7440e276152cb9d7727f945059
3 files changed