ARM: dts: imx6qdl-pico: Fix Ethernet support

Currently, it is no longer possible to retrieve a DHCP address
on the imx6qdl-pico board.

This issue has been exposed by commit f5d9aa79 ("ARM: imx6q:
remove clk-out fixup for the Atheros AR8031 and AR8035 PHYs").

Fix it by describing the qca,clk-out-frequency property as suggested
by the commit above.

Fixes: 98670a0b ("ARM: dts: imx6qdl: Add imx6qdl-pico support")
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

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

@@ -176,7 +176,18 @@ &fec {
 	pinctrl-0 = <&pinctrl_enet>;
 	phy-mode = "rgmii-id";
 	phy-reset-gpios = <&gpio1 26 GPIO_ACTIVE_LOW>;
+	phy-handle = <&phy>;
 	status = "okay";
+
+	mdio {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		phy: ethernet-phy@1 {
+			reg = <1>;
+			qca,clk-out-frequency = <125000000>;
+		};
+	};
 };
 
 &hdmi {