dt-bindings: add RK3368-uQ7 SoM and EVK base board

RK3368-uQ7 is a Qseven compatible system-on-module by Theobroma Systems.

This adds the module and the EVK baseboard "Haikou"

Signed-off-by: Klaus Goger <klaus.goger@theobroma-systems.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>