cubox-i: add u-boot fork for cubox-i machines

This fork includes MXC SPL support for the SolidRun CuBox-i and
HummingBoard devices

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
cubox-i: add customized kernel

This kernel is based on linux-imx 3.0.35, and adds patches for
CuBox-i and HummingBoard support

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
cubox-i: add machine config

The new cubox-i machine config produces images that can be used for
all CuBox-i and HummingBoard devices (u-boot SPL autodetects the platform)

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>