Amazon Kindle Fire (first generation) codename kc1 support

The Amazon Kindle Fire (first generation) codename kc1 is a tablet that was
released by Amazon back in 2011.

It is using an OMAP4430 SoC GP version, which allows running U-Boot and the
U-Boot SPL from the ground up.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>