ARM: dts: r8a7744-iwg20m: Add eMMC support

Add eMMC support for iWave RZ/G1N Qseven System On Module.
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/r8a7744-iwg20m.dtsi

@@ -29,3 +29,20 @@ reg_3p3v: 3p3v {
 &extal_clk {
 	clock-frequency = <20000000>;
 };
+
+&pfc {
+	mmcif0_pins: mmc {
+		groups = "mmc_data8_b", "mmc_ctrl";
+		function = "mmc";
+	};
+};
+
+&mmcif0 {
+	pinctrl-0 = <&mmcif0_pins>;
+	pinctrl-names = "default";
+
+	vmmc-supply = <&reg_3p3v>;
+	bus-width = <8>;
+	non-removable;
+	status = "okay";
+};