ARM: sun7i: Add the pin muxing options for the I2C controllers

The A20 boards we currently have share the same pins for the i2c
controllers they share. Add them to the DTSI.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun7i-a20.dtsi

@@ -215,6 +215,27 @@
 				allwinner,pull = <0>;
 			};
 
+			i2c0_pins_a: i2c0@0 {
+				allwinner,pins = "PB0", "PB1";
+				allwinner,function = "i2c0";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			i2c1_pins_a: i2c1@0 {
+				allwinner,pins = "PB18", "PB19";
+				allwinner,function = "i2c1";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			i2c2_pins_a: i2c2@0 {
+				allwinner,pins = "PB20", "PB21";
+				allwinner,function = "i2c2";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
 			emac_pins_a: emac0@0 {
 				allwinner,pins = "PA0", "PA1", "PA2",
 						"PA3", "PA4", "PA5", "PA6",