ARM: dts: Enable emmc on hp t410

There's a 2GB emmc on hp t410 that's wired to the sd_2 interface.
Note that we also need to configure the evtmux using edma_xbar for
edma channels.

Let's use the McASP2 channels like the original kernel seems to be
doing, most likely the audio on t410 is different from dm814x-evm.
Reviewed-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/boot/dts/dm8148-t410.dts

@@ -15,6 +15,13 @@
 		device_type = "memory";
 		reg = <0x80000000 0x40000000>;	/* 1 GB */
 	};
+
+	vmmcsd_fixed: fixedregulator@0 {
+		compatible = "regulator-fixed";
+		regulator-name = "vmmcsd_fixed";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+	};
 };
 
 &cpsw_emac0 {
@@ -26,3 +33,31 @@
 	phy_id = <&davinci_mdio>, <1>;
 	phy-mode = "rgmii";
 };
+
+&mmc3 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&sd2_pins>;
+	vmmc-supply = <&vmmcsd_fixed>;
+	bus-width = <8>;
+	dmas = <&edma_xbar 8 0 1	/* use SDTXEVT1 instead of MCASP0TX */
+		&edma_xbar 9 0 2>;	/* use SDRXEVT1 instead of MCASP0RX */
+	dma-names = "tx", "rx";
+};
+
+&pincntl {
+	sd2_pins: pinmux_sd2_pins {
+		pinctrl-single,pins = <
+			DM814X_IOPAD(0x09c0, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[7] */
+			DM814X_IOPAD(0x09c4, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[6] */
+			DM814X_IOPAD(0x09c8, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[5] */
+			DM814X_IOPAD(0x09cc, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[4] */
+			DM814X_IOPAD(0x09d0, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[3] */
+			DM814X_IOPAD(0x09d4, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[2] */
+			DM814X_IOPAD(0x09d8, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[1] */
+			DM814X_IOPAD(0x09dc, PIN_INPUT_PULLUP | 0x1)	/* SD2_DAT[0] */
+			DM814X_IOPAD(0x09e0, PIN_INPUT | 0x1)		/* SD2_CLK */
+			DM814X_IOPAD(0x09f4, PIN_INPUT_PULLUP | 0x2)	/* SD2_CMD */
+			DM814X_IOPAD(0x0920, PIN_INPUT | 40)	/* SD2_SDCD */
+			>;
+	};
+};