arm64: dts: rockchip: Add on-board WiFi/BT support for Rock960 boards

Add on-board WiFi/BT support for Rock960 boards such as Rock960 based
on AP6356S and Ficus based on AP6354 wireless modules.

Firmwares for the respective boards are available here:

http://people.linaro.org/~manivannan.sadhasivam/rock960_wifi/
http://people.linaro.org/~manivannan.sadhasivam/ficus_wifi/



Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>