Odroid-XU3: Add eMMC-reset node on DT

This needs for special handling of nRESET_OUT line(GPD1-0 gpio) for eMMC
memory to perform complete reboot on Odroid XU3 board.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

arch/arm/dts/exynos5422-odroidxu3.dts

@@ -46,4 +46,9 @@
 	mmc@12220000 {
 		fifoth_val = <0x201f0020>;
 	};
+
+	emmc-reset {
+		compatible = "samsung,emmc-reset";
+		reset-gpio = <&gpd1 0 0>;
+	};
 };