ARM: shmobile: silk: add I2C1 DT support

Define the SILK board dependent part of the I2C1 device node.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7794-silk.dts

@@ -61,6 +61,11 @@
 		renesas,function = "intc";
 	};
 
+	i2c1_pins: i2c1 {
+		renesas,groups = "i2c1";
+		renesas,function = "i2c1";
+	};
+
 	mmcif0_pins: mmcif0 {
 		renesas,groups = "mmc_data8", "mmc_ctrl";
 		renesas,function = "mmc";
@@ -95,6 +100,14 @@
 	};
 };
 
+&i2c1 {
+	pinctrl-0 = <&i2c1_pins>;
+	pinctrl-names = "default";
+
+	status = "okay";
+	clock-frequency = <400000>;
+};
+
 &mmcif0 {
 	pinctrl-0 = <&mmcif0_pins>;
 	pinctrl-names = "default";