soc: rockchip: power-domain: add power domain support for px30

This driver is modified to support PX30 SoC.

Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>