arm64: dts: rockchip: Make RK3588 GPU OPP table naming less generic

arm64: dts: rockchip: Make RK3588 GPU OPP table naming less generic

Unify the naming of the existing GPU OPP table nodes found in the RK3588
and RK3588J SoC dtsi files with the other SoC's GPU OPP nodes, following
the more "modern" node naming scheme.

Fixes: a7b2070505a2 ("arm64: dts: rockchip: Split GPU OPPs of RK3588 and RK3588j")
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
[opp-table also is way too generic on systems with like 4-5 opp-tables]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>