arm64: dts: rockchip: Add dynamic-power-coefficient to rk3399 GPU

arm64: dts: rockchip: Add dynamic-power-coefficient to rk3399 GPU

Add dynamic-power-coefficient to the GPU node. That will create Energy
Model for the GPU based on the coefficient and OPP table information.
It will enable mechanism such as DTMP or IPA to work with the GPU DVFS.
In similar way the Energy Model for CPUs in rk3399 is created, so both
are aligned in power scale. The maximum power used from this coefficient
is 1.5W at 600MHz.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20231127081511.1911706-1-lukasz.luba@arm.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>