Add support for Versatile Express, with the configs+rules for image
creation and bootspec entries.
Note that vexpress in qemu can currently only boot from nor, so we put
the bootloader, environment and boot state there and the rest of the
system into mmc.
Signed-off-by: Rouven Czerwinski <firstname.lastname@example.org>
Signed-off-by: Chris Fiege <email@example.com>
[improve commit description]
[split from vexpress patches]
[fix and cleanupimage generation]
Signed-off-by: Robert Schwebel <firstname.lastname@example.org>