ARM: dts: imx6: edmqmx6: set phy-mode to RGMII-ID

Latest kernel is actually using phy-mode property, so set proper value to make
fec interface work again.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6q-dmo-edmqmx6.dts

@@ -112,7 +112,7 @@ flash: m25p80@0 {
 &fec {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_enet>;
-	phy-mode = "rgmii";
+	phy-mode = "rgmii-id";
 	phy-reset-gpios = <&gpio1 25 GPIO_ACTIVE_LOW>;
 	phy-supply = <&vgen2_1v2_eth>;
 	status = "okay";