Odroid: Add eMMC-reset node on DT

This needs for special handling of nRESET_OUT line(GPK1-2 gpio) for eMMC
memory to perform complete reboot on Odroid X2/U3 boards.

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

arch/arm/dts/exynos4412-odroid.dts

@@ -85,4 +85,9 @@
 			reg = <0x125B0000 0x100>;
 		};
 	};
+
+	emmc-reset {
+		compatible = "samsung,emmc-reset";
+		reset-gpio = <&gpk1 2 0>;
+	};
 };