ARM: dts: sun8i: v40: bananapi-m2-berry: Fix ethernet node

Ethernet PHY on BananaPi M2 Berry provides RX and TX delays. Fix ethernet
node to reflect that fact.

Fixes: 27e81e1 ("ARM: dts: sun8i: v40: bananapi-m2-berry: Enable GMAC ethernet controller")
Signed-off-by: Pablo Greco <pgreco@centosproject.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/1604326769-39802-1-git-send-email-pgreco@centosproject.org

arch/arm/boot/dts/sun8i-v40-bananapi-m2-berry.dts

@@ -120,7 +120,7 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&gmac_rgmii_pins>;
 	phy-handle = <&phy1>;
-	phy-mode = "rgmii";
+	phy-mode = "rgmii-id";
 	phy-supply = <&reg_dc1sw>;
 	status = "okay";
 };