Co-authored-by: Luke Childs <lukechilds123@gmail.com>

1. Added 'fatcat' to extract from the boot filesystem from a
   standard RPI image
2. Added qemu-system-aarch64 to support raspi3 machines
3. Extracted images to search for kernel7/8.img and correct dtb
   files to boot kernel
4. Disabled nic for raspi2/3 as USB is not supported (yet)
Co-authored-by: James Reynolds <james.reynolds@cristiesoftware.com>
Co-authored-by: James Reynolds <james.reynolds@cristie.com>
Co-authored-by: Luke Childs <lukechilds123@gmail.com>

This reverts commit 6115945a.

Extract a pre-existing image there if one doesn't already exist