ARM: dts: iwg22m: Add eMMC support

Add eMMC support for iW-RainboW-G22M-SM.
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7745-iwg22m.dtsi

@@ -17,8 +17,34 @@ memory@40000000 {
 		device_type = "memory";
 		reg = <0 0x40000000 0 0x20000000>;
 	};
+
+	reg_3p3v: 3p3v {
+		compatible = "regulator-fixed";
+		regulator-name = "3P3V";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-always-on;
+		regulator-boot-on;
+	};
 };
 
 &extal_clk {
 	clock-frequency = <20000000>;
 };
+
+&pfc {
+	mmcif0_pins: mmc {
+		groups = "mmc_data8", "mmc_ctrl";
+		function = "mmc";
+	};
+};
+
+&mmcif0 {
+	pinctrl-0 = <&mmcif0_pins>;
+	pinctrl-names = "default";
+
+	vmmc-supply = <&reg_3p3v>;
+	bus-width = <8>;
+	non-removable;
+	status = "okay";
+};