ARM64: dts: meson-axg: fix ethernet stability issue

Like the odroid-c2 and wetek, the s400 uses the RTL8211F and seems to
suffer from the kind of stability issue.

Doing an iperf3 download test, we can see a significant number of LPI
interrupts on the tx path. After a short while (5 to 15 seconds), the
network connection dies. If using rootfs over NFS, the connection may
also break during the boot sequence.

We still don't have a real explanation for this problem so let's disable
EEE once again.

Fixes: f6f6ac914b82 ("ARM64: dts: meson-axg: enable ethernet for A113D S400 board")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-axg-s400.dts

@@ -66,9 +66,22 @@
 
 &ethmac {
 	status = "okay";
-	phy-mode = "rgmii";
 	pinctrl-0 = <&eth_rgmii_y_pins>;
 	pinctrl-names = "default";
+	phy-handle = <&eth_phy0>;
+	phy-mode = "rgmii";
+
+	mdio {
+		compatible = "snps,dwmac-mdio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		eth_phy0: ethernet-phy@0 {
+			/* Realtek RTL8211F (0x001cc916) */
+			reg = <0>;
+			eee-broken-1000t;
+		};
+	};
 };
 
 &uart_A {