arm64: dts: imx8mm-evk: add phy-reset-gpios for fec1

imx8mm-evk has a GPIO connected to AR8031 Ethernet PHY's reset pin.

Describe it in the device tree, following phy's datasheet reset duration of 10ms.

Tested booting via NFS.
Signed-off-by: Alifer Moraes <alifer.wsdm@gmail.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mm-evk.dts

@@ -107,6 +107,8 @@ &fec1 {
 	pinctrl-0 = <&pinctrl_fec1>;
 	phy-mode = "rgmii-id";
 	phy-handle = <&ethphy0>;
+	phy-reset-gpios = <&gpio4 22 GPIO_ACTIVE_LOW>;
+	phy-reset-duration = <10>;
 	fsl,magic-packet;
 	status = "okay";