arm: mvebu: armada-3720-turris-mox.dts: Fix dtc warning

Fix this dtc warning:
Warning (avoid_default_addr_size)

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Marek BehĂșn <marek.behun@nic.cz>
diff --git a/arch/arm/dts/armada-3720-turris-mox.dts b/arch/arm/dts/armada-3720-turris-mox.dts
index a1e0ad5..0f0a6ce 100644
--- a/arch/arm/dts/armada-3720-turris-mox.dts
+++ b/arch/arm/dts/armada-3720-turris-mox.dts
@@ -100,6 +100,8 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&i2c1_pins>;
 	status = "okay";
+	#address-cells = <1>;
+	#size-cells = <0>;
 
 	rtc@6f {
 		compatible = "microchip,mcp7941x";