arm: dts: rockchip: add some common pin-settings to rk3399

Those pins would be used by many boards.

Commit grabbed from Linux:

commit b41023282d07b61a53e2c9b9508912b1e7ce7b4f
Author: Randy Li <ayaka@soulik.info>
Date:   Thu Jun 21 21:32:10 2018 +0800

    arm64: dts: rockchip: add some common pin-settings to rk3399

    Those pins would be used by many boards.

Signed-off-by: Randy Li <ayaka@soulik.info>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: Randy Li <ayaka@soulik.info>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>