Comment 5 for bug 1640519

Bug 1160360 says it is fix-released, and that flash-kernel will not run inside an lxc container. If that is a complete solution, then we could potentially add u-boot-tools to the squashfs image also.
Dan's comment at https://bugs.launchpad.net/maas-images/+bug/1337538/comments/8 describes this well, and also where we could pull logic to decide if installation is necessary.