arm64: dts: rockchip: Add rk3328 io-domain node

Add the core grf subnode for the io-domain controller.
Signed-off-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3328.dtsi

@@ -162,6 +162,11 @@ grf: syscon@ff100000 {
 		#address-cells = <1>;
 		#size-cells = <1>;
 
+		io_domains: io-domains {
+			compatible = "rockchip,rk3328-io-voltage-domain";
+			status = "disabled";
+		};
+
 		power: power-controller {
 			compatible = "rockchip,rk3328-power-controller";
 			#power-domain-cells = <1>;