arm64: dts: rockchip: add rk3588 gpio aliases to soc dtsi

arm64: dts: rockchip: add rk3588 gpio aliases to soc dtsi

The gpio controllers on rk3588 are named gpio0 - gpio4. Board schematics
also use these exact numbers and we want those names to also reflect
in the OS devices because everything else would just cause confusion.
Userspace gpio access is a thing afterall.

To prevent each board repeating their list of gpio aliases, define them
in the soc dtsi, as previous Rockchip soc like the rk356x do already.

Signed-off-by: Heiko Stuebner <heiko.stuebner@cherry.de>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Link: https://lore.kernel.org/r/20231205164842.556684-4-heiko@sntech.de