arm64: dts: rockchip: add GPU powerdomain, opps, and cooling to rk3328

arm64: dts: rockchip: add GPU powerdomain, opps, and cooling to rk3328

Add GPU powerdomain, opp-table, and cooling map nodes for the Mali
GPU on the RK3328 SoC. Opp-table frequencies are sourced from the
Rockchip Linux v4.4 vendor kernel while voltages have been derived
from practical use and support work: keeping voltage above 1075mV
and disabling the 500MHz opp-point avoids instability and crashes.

Signed-off-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Tested-by: Diederik de Haas <didi.debian@cknow.org>  # Rock64
Link: https://lore.kernel.org/r/20250906120810.1833016-1-christianshewitt@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>