arm64: dts: imx8mn-evk: add hardware reset for FEC PHY

Add hardware reset for FEC PHY.
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi

@@ -97,6 +97,8 @@ mdio {
 		ethphy0: ethernet-phy@0 {
 			compatible = "ethernet-phy-ieee802.3-c22";
 			reg = <0>;
+			reset-gpios = <&gpio4 22 GPIO_ACTIVE_LOW>;
+			reset-assert-us = <10000>;
 		};
 	};
 };