arm64: dts: rockchip: switch rk3399-gru boards to enable-gpios

The recommended name for enable GPIOs property in regulator-gpio is
enable-gpios.  This is also required by bindings:

  rk3399-gru-bob.dtb: ppvar-sd-card-io: Unevaluated properties are not allowed ('enable-gpio' was unexpected)

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230725142616.157405-1-krzysztof.kozlowski@linaro.org


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