tools: sunxi: Add spl image builder
This program generates raw SPL images that can be flashed on the NAND with
the ECC and randomizer properly set up.
This has been copied (and tweaked to find the right headers) from the
sunxi-tools (https://github.com/linux-sunxi/sunxi-tools) upstream
repository, commit
1c3a6ca5.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>