arm64: dts: meson: g12a: add mdio multiplexer

Add the g12a mdio multiplexer which allows to connect to either
an external phy through the SoC pins or the internal 10/100 phy
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Acked-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: NKevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-g12a.dtsi

@@ -1698,6 +1698,38 @@
 				assigned-clock-rates = <100000000>;
 				#phy-cells = <1>;
 			};
+
+			eth_phy: mdio-multiplexer@4c000 {
+				compatible = "amlogic,g12a-mdio-mux";
+				reg = <0x0 0x4c000 0x0 0xa4>;
+				clocks = <&clkc CLKID_ETH_PHY>,
+					 <&xtal>,
+					 <&clkc CLKID_MPLL_50M>;
+				clock-names = "pclk", "clkin0", "clkin1";
+				mdio-parent-bus = <&mdio0>;
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				ext_mdio: mdio@0 {
+					reg = <0>;
+					#address-cells = <1>;
+					#size-cells = <0>;
+				};
+
+				int_mdio: mdio@1 {
+					reg = <1>;
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					internal_ephy: ethernet_phy@8 {
+						compatible = "ethernet-phy-id0180.3301",
+							     "ethernet-phy-ieee802.3-c22";
+						interrupts = <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>;
+						reg = <8>;
+						max-speed = <100>;
+					};
+				};
+			};
 		};
 
 		aobus: bus@ff800000 {