ARM: shmobile: r8a7791: add EtherAVB DT support

Define the generic R8A7791 part of the EtherAVB device node.

Based on the commit f25d6b97 ("ARM: shmobile: r8a7790: add EtherAVB DT
support").
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7791.dtsi

@@ -785,6 +785,18 @@ ether: ethernet@ee700000 {
 		status = "disabled";
 	};
 
+	avb: ethernet@e6800000 {
+		compatible = "renesas,etheravb-r8a7791",
+			     "renesas,etheravb-rcar-gen2";
+		reg = <0 0xe6800000 0 0x800>, <0 0xee0e8000 0 0x4000>;
+		interrupts = <0 163 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&mstp8_clks R8A7791_CLK_ETHERAVB>;
+		power-domains = <&cpg_clocks>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		status = "disabled";
+	};
+
 	sata0: sata@ee300000 {
 		compatible = "renesas,sata-r8a7791";
 		reg = <0 0xee300000 0 0x2000>;