Fix xbmc-imx on linux-imx6-wandboard-dt

This fixes building xbmc on linux-imx6-wandboard-dt.
It should be compatible with other imx6 devices (cubox).
@pepedog please approve.

It also adds a patch to enable running xbmc on the wandboard-dt kernel (see xbmc-imx6/xbmc#51).

Cheers