dde_linux: initial i.MX6 usb support [HALTED]

Unfortunatly, most if not all i.MX6 changes are currently not in the
mainline kernel. The version used by the Cubox-i is still on version
3.0.35 with a lot of patches, even in common places (e.g. usb/core).
Incorporating these changes into our current dde_linux based on 3.9
is not feasable without much effort. So for this work is halted.