dt-bindings: add rk3399-q7 SoM

RK3399-Q7 is a Qseven compatible system-on-module by Theobroma Systems.

This adds the module and the EVK baseboard "Haikou"
Signed-off-by: NKlaus Goger <klaus.goger@theobroma-systems.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/arm/rockchip.txt

@@ -181,6 +181,10 @@ Rockchip platforms device tree bindings
     Required root node properties:
       - compatible = "rockchip,rk3399-sapphire-excavator", "rockchip,rk3399";
 
+- Theobroma Systems RK3399-Q7 Haikou Baseboard:
+    Required root node properties:
+      - compatible = "tsd,rk3399-q7-haikou", "rockchip,rk3399";
+
 - Tronsmart Orion R68 Meta
     Required root node properties:
       - compatible = "tronsmart,orion-r68-meta", "rockchip,rk3368";