ARM: dts: imx6sx-sdb: add i2c3 node

This patch adds node i2c bus 3 to get the appropriate userland device
file. So for prototyping it's possible to experiment within userland.

Signed-off-by: Christoph Fritz <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

arch/arm/boot/dts/imx6sx-sdb.dtsi

···
 	status = "okay";
 };
 
+&i2c3 {
+	clock-frequency = <100000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_i2c3>;
+	status = "okay";
+};
+
 &i2c4 {
         clock-frequency = <100000>;
         pinctrl-names = "default";
···
 			fsl,pins = <
 				MX6SX_PAD_GPIO1_IO01__I2C1_SDA		0x4001b8b1
 				MX6SX_PAD_GPIO1_IO00__I2C1_SCL		0x4001b8b1
+			>;
+		};
+
+		pinctrl_i2c3: i2c3grp {
+			fsl,pins = <
+				MX6SX_PAD_KEY_ROW4__I2C3_SDA		0x4001b8b1
+				MX6SX_PAD_KEY_COL4__I2C3_SCL		0x4001b8b1
 			>;
 		};