ARM64: dts: meson-gxbb-odroidc2: add the ethernet PHY's reset GPIO

This resets the ethernet PHY during boot to get the PHY into a "clean"
state. While here also explicitly specify the phy-mode instead of
relying on the default-value from meson-gx.dtsi.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts

@@ -152,6 +152,11 @@ &ethmac {
 	pinctrl-0 = <&eth_rgmii_pins>;
 	pinctrl-names = "default";
 	phy-handle = <&eth_phy0>;
+	phy-mode = "rgmii";
+
+	snps,reset-gpio = <&gpio GPIOZ_14 0>;
+	snps,reset-delays-us = <0 10000 1000000>;
+	snps,reset-active-low;
 
 	mdio {
 		compatible = "snps,dwmac-mdio";