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

arch/arm64/boot/dts/rockchip/rk3588s.dtsi

@@ -19,6 +19,11 @@ / {
 	#size-cells = <2>;
 
 	aliases {
+		gpio0 = &gpio0;
+		gpio1 = &gpio1;
+		gpio2 = &gpio2;
+		gpio3 = &gpio3;
+		gpio4 = &gpio4;
 		i2c0 = &i2c0;
 		i2c1 = &i2c1;
 		i2c2 = &i2c2;