arm64: dts: actions: Add uSD and eMMC support for Bubblegum96

Add uSD and eMMC support for Bubblegum96 board based on Actions Semi
S900 SoC. SD0 is connected to uSD slot and SD2 is connected to eMMC.
Since there is no PMIC support added yet, fixed regulator has been
used as a regulator node.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

arch/arm64/boot/dts/actions/s900-bubblegum-96.dts

@@ -12,6 +12,9 @@ / {
 	model = "Bubblegum-96";
 
 	aliases {
+		mmc0 = &mmc0;
+		mmc1 = &mmc1;
+		mmc2 = &mmc2;
 		serial5 = &uart5;
 	};
 
@@ -23,6 +26,24 @@ memory@0 {
 		device_type = "memory";
 		reg = <0x0 0x0 0x0 0x80000000>;
 	};
+
+	/* Fixed regulator used in the absence of PMIC */
+	vcc_3v1: vcc-3v1 {
+		compatible = "regulator-fixed";
+		regulator-name = "fixed-3.1V";
+		regulator-min-microvolt = <3100000>;
+		regulator-max-microvolt = <3100000>;
+		regulator-always-on;
+	};
+
+	/* Fixed regulator used in the absence of PMIC */
+	sd_vcc: sd-vcc {
+		compatible = "regulator-fixed";
+		regulator-name = "fixed-3.1V";
+		regulator-min-microvolt = <3100000>;
+		regulator-max-microvolt = <3100000>;
+		regulator-always-on;
+	};
 };
 
 &i2c0 {
@@ -241,6 +262,47 @@ pinconf {
 			bias-pull-up;
 		};
 	};
+
+	mmc0_default: mmc0_default {
+		pinmux {
+			groups = "sd0_d0_mfp", "sd0_d1_mfp", "sd0_d2_d3_mfp",
+				 "sd0_cmd_mfp", "sd0_clk_mfp";
+			function = "sd0";
+		};
+	};
+
+	mmc2_default: mmc2_default {
+		pinmux {
+			groups = "nand0_d0_ceb3_mfp";
+			function = "sd2";
+		};
+	};
+};
+
+/* uSD */
+&mmc0 {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&mmc0_default>;
+	no-sdio;
+	no-mmc;
+	no-1-8-v;
+	cd-gpios = <&pinctrl 120 GPIO_ACTIVE_LOW>;
+	bus-width = <4>;
+	vmmc-supply = <&sd_vcc>;
+	vqmmc-supply = <&sd_vcc>;
+};
+
+/* eMMC */
+&mmc2 {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&mmc2_default>;
+	no-sdio;
+	no-sd;
+	non-removable;
+	bus-width = <8>;
+	vmmc-supply = <&vcc_3v1>;
 };
 
 &timer {