ARM: dts: rockchip: add MiQi board from mqmaker

The MiQi is a rk3288-based devboard from Shenzen based mqmaker, with a
footprint the size of a credit card.

Main available outside connections are 4 usb ports, hdmi, gigabit
ethernet and two expansion headers.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>