PM / AVS: rockchip-io: add io selectors and supplies for PX30

This adds the necessary data for handling io voltage domains on PX30.
As interesting tidbit, the PX30 contains two separate iodomain areas.
One in the regular General Register Files (GRF) and one in PMUGRF in the
pmu power domain.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>