arm64: dts: rockchip: add RK3399 Gru gpio-line-names

It's convenient to get nice names for GPIOs. In particular, Chrome OS
tooling looks for "AP_FLASH_WP" and "AP_FLASH_WP_L". The rest are
provided for convenience.

Gru-Bob and Gru-Kevin share the gru-chromebook.dtsi, and for the most
part they share pin meanings. I omitted a few areas where components
were available only on one or the other.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20210820133829.1.Ica46f428de8c3beb600760dbcd63cf879ec24baf@changeid


Signed-off-by: Heiko Stuebner <heiko@sntech.de>