ARM: dts: imx6qdl-tx6: add mdio node for ethernet phy

Add mdio node and an appropriate PHY configuration to enable use of
the PHY interrupt for link status changes.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-tx6.dtsi

@@ -265,8 +265,22 @@ &fec {
 	clock-names = "ipg", "ahb", "ptp", "enet_out";
 	phy-mode = "rmii";
 	phy-reset-gpios = <&gpio7 6 GPIO_ACTIVE_HIGH>;
+	phy-handle = <&etnphy>;
 	phy-supply = <&reg_3v3_etn>;
 	status = "okay";
+
+	mdio {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		etnphy: ethernet-phy@0 {
+			compatible = "ethernet-phy-ieee802.3-c22";
+			reg = <0>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&pinctrl_enet_mdio>;
+			interrupts-extended = <&gpio7 1 IRQ_TYPE_EDGE_FALLING>;
+		};
+	};
 };
 
 &gpmi {