arm64: dts: rockchip: Add GPU OPP voltage ranges to RK356x SoC dtsi

arm64: dts: rockchip: Add GPU OPP voltage ranges to RK356x SoC dtsi

Add support for voltage ranges to the GPU OPPs defined in the SoC dtsi for
Rockchip RK356x.  This is, for example, useful for RK356x-based boards that
are designed to use the same power supply for the GPU and NPU portions of
the SoC, which is described further in the following documents:

  - Rockchip RK3566 Hardware Design Guide, version 1.1.0, page 37
  - Rockchip RK3568 Hardware Design Guide, version 1.2, page 78

The values for the exact GPU OPP voltages and the lower limits for the GPU
OPP voltage ranges differ from the values found in the vendor kernel source
(cf. downstream commit f8b9431ee38e ("arm64: dts: rockchip: rk3568: support
adjust opp-table by otp")), [1][2] and present the exact GPU OPP voltage
values that have served us well so far.

[1] https://github.com/rockchip-linux/kernel/commit/f8b9431ee38ed561650be7092ab93f564598daa9
[2] https://raw.githubusercontent.com/rockchip-linux/kernel/f8b9431ee38ed561650be7092ab93f564598daa9/arch/arm64/boot/dts/rockchip/rk3568.dtsi

Suggested-by: Diederik de Haas <didi.debian@cknow.org>
Helped-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Link: https://lore.kernel.org/r/7e9ba70fd54a21d6f1f267df11e0acabff8d24e0.1719763100.git.dsimic@manjaro.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>