ARM: shmobile: genmai: adapt dts to use native i2c driver

Activate the shiny new riic driver for i2c2. Tested by accessing the
eeprom on the genmai board.
Signed-off-by: NWolfram Sang <wsa@sang-engineering.com>
Acked-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r7s72100-genmai-reference.dts

@@ -29,3 +29,14 @@
 		#size-cells = <1>;
 	};
 };
+
+&i2c2 {
+	status = "okay";
+	clock-frequency = <400000>;
+
+	eeprom@50 {
+		compatible = "renesas,24c128";
+		reg = <0x50>;
+		pagesize = <64>;
+	};
+};