ARM: dts: iwg23s-sbc: Enable RTC

Enable NXP pcf85263 real time clock for the iWave SBC based on RZ/G1C.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a77470-iwg23s-sbc.dts

@@ -84,12 +84,30 @@ &extal_clk {
 	clock-frequency = <20000000>;
 };
 
+&i2c3 {
+	pinctrl-0 = <&i2c3_pins>;
+	pinctrl-names = "default";
+
+	status = "okay";
+	clock-frequency = <400000>;
+
+	rtc@51 {
+		compatible = "nxp,pcf85263";
+		reg = <0x51>;
+	};
+};
+
 &pfc {
 	avb_pins: avb {
 		groups = "avb_mdio", "avb_gmii_tx_rx";
 		function = "avb";
 	};
 
+	i2c3_pins: i2c3 {
+		groups = "i2c3_c";
+		function = "i2c3";
+	};
+
 	mmc_pins_uhs: mmc_uhs {
 		groups = "mmc_data8", "mmc_ctrl";
 		function = "mmc";