arm64: dts: renesas: r8a77970: Connect Ethernet-AVB to IPMMU-RT

Add IPMMU-RT to the Ethernet-AVB device node.

Based on work by Magnus Damm for the r8a7795.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/r8a77970.dtsi

@@ -440,6 +440,7 @@ avb: ethernet@e6800000 {
 			power-domains = <&sysc 32>;
 			resets = <&cpg 812>;
 			phy-mode = "rgmii-id";
+			iommus = <&ipmmu_rt 3>;
 			#address-cells = <1>;
 			#size-cells = <0>;
 		};