arm64: dts: rockchip: add 96boards RK3399 Ficus board

The RK3399 Ficus board is an Enterprise Edition board
manufactured by Vamrs Ltd., based on the Rockchip RK3399 SoC.

The board exposes a bunch of nice peripherals, including
SATA, HDMI, MIPI CSI, Ethernet, WiFi, and PCIe.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>