ARM: dts: rockchip: add thermal nodes for RV1108 SoC

Add thermal zone and dynamic CPU power coefficients for RV1108

Signed-off-by: Rocky Hao <rocky.hao@rock-chips.com>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>