arm64: dts: rockchip: add gpio alias for gpio dt nodes

arm64: dts: rockchip: add gpio alias for gpio dt nodes

Rockchip SoC TRM, SoC datasheet and board schematics always refer to
the same gpio numbers - even if not all are used for a specific board.
In order to not have to re-define them for every board add the
aliases to SoC dtsi files.

Co-developed-by: Jianqun Xu <jay.xu@rock-chips.com>
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Link: https://lore.kernel.org/r/56daeead-1d35-44bb-00c0-614b84a986de@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>