arm64: dts: imx8mq-phanbell: Fix Ethernet PHY post-reset duration

i.MX8MQ Phanbell board uses Realtek RTL8211FD as Ethernet PHY.
Its datasheet states that the proper post reset duration should be at least 50 ms.

Fixes: f34d4bfa ("arm64: dts: imx8mq-phanbell: Add support for ethernet")
Signed-off-by: Alifer Moraes <alifer.wsdm@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq-phanbell.dts

@@ -264,7 +264,7 @@ &fec1 {
 	phy-mode = "rgmii-id";
 	phy-reset-gpios = <&gpio1 9 GPIO_ACTIVE_LOW>;
 	phy-reset-duration = <10>;
-	phy-reset-post-delay = <30>;
+	phy-reset-post-delay = <50>;
 	phy-handle = <&ethphy0>;
 	fsl,magic-packet;
 	status = "okay";