ARM: dts: Add micro SD card SDHCI node for exynos4412-trats

Add SDHCI node for supporting the micro SD card. On Trats2 board the
SDHCI does not use sd2_cd pins (gpk2-2) for card detect but gpx3-4
instead.

Power is supplied from LDO21 regulator which in off state is controlled
by external GPIO pin.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos4412-trats2.dts

@@ -563,6 +563,16 @@ mmc@12550000 {
 		cap-mmc-highspeed;
 	};
 
+	sdhci@12530000 {
+		bus-width = <4>;
+		cd-gpios = <&gpx3 4 0>;
+		cd-inverted;
+		pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_bus4>;
+		pinctrl-names = "default";
+		vmmc-supply = <&ldo21_reg>;
+		status = "okay";
+	};
+
 	serial@13800000 {
 		status = "okay";
 	};