ARM: sun6i: Enable the I2C muxing options

The i2c controllers have a few muxing options on the A31. Enable the
ones found in the A31 Colombus board.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun6i-a31.dtsi

@@ -257,6 +257,27 @@ uart0_pins_a: uart0@0 {
 				allwinner,drive = <0>;
 				allwinner,pull = <0>;
 			};
+
+			i2c0_pins_a: i2c0@0 {
+				allwinner,pins = "PH14", "PH15";
+				allwinner,function = "i2c0";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			i2c1_pins_a: i2c1@0 {
+				allwinner,pins = "PH16", "PH17";
+				allwinner,function = "i2c1";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			i2c2_pins_a: i2c2@0 {
+				allwinner,pins = "PH18", "PH19";
+				allwinner,function = "i2c2";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
 		};
 
 		ahb1_rst: reset@01c202c0 {