ARM: dts: imx6qdl-wandboard: Fix Ethernet support

Currently, the imx6q-wandboard Ethernet does not transmit any
data.

This issue has been exposed by commit f5d9aa79df ("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: 77591e4245 ("ARM: dts: imx6qdl-wandboard: add ethernet PHY description")
Signed-off-by: Martin Haaß <vvvrrooomm@gmail.com>
Tested-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

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

@@ -309,6 +309,7 @@
 
 		ethphy: ethernet-phy@1 {
 			reg = <1>;
+			qca,clk-out-frequency = <125000000>;
 		};
 	};
 };