warp7: Convert to OF_UPSTREAM

Instead of using the local imx7s-warp devicetree copies from U-Boot,
convert the imx7s-warp board to OF_UPSTREAM so that the upstream
kernel devicetree can be used instead.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
5 files changed