dt-bindings: ARM: dts: rockchip: Add bindings for rk3288-veyron-{fievel,tiger}

Fievel is a Chromebox and Tiger a Chromebase with a 10" display and
touchscreen. Tiger and Fievel are based on the same board.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>