ARM: dts: imx6qdl-icore-1.5: Remove duplicate phy reset methods

Engicam i.CoreM6 1.5 Quad/Dual MIPI dtsi is reusing fec node
from Engicam i.CoreM6 dtsi but have sampe copy of phy-reset-gpio
and phy-mode properties.

So, drop this phy reset methods from imx6qdl-icore-1.5 dsti file.

Cc: Jacopo Mondi <[e-mail]>
Signed-off-by: Michael Trimarchi <[e-mail]>
Signed-off-by: Jagan Teki <[e-mail]>
Tested-by: Jacopo Mondi <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

arch/arm/boot/dts/imx6qdl-icore-1.5.dtsi

···
 &fec {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_enet>;
-	phy-reset-gpios = <&gpio7 12 GPIO_ACTIVE_LOW>;
 	clocks = <&clks IMX6QDL_CLK_ENET>,
 		 <&clks IMX6QDL_CLK_ENET>,
 		 <&clks IMX6QDL_CLK_ENET_REF>;
-	phy-mode = "rmii";
 	status = "okay";
 };