arm64: dts: rockchip: add Haikou baseboard with RK3368-uQ7 SoM

Haikou is a Qseven and μQseven baseboard used in Theobroma Systems
evaluation kits. This dts adds a version for use with a RK3368-uQ7 SoM
called Lion.

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