ARM: dts: Fix MMC pinctrl for exynos5250-snow

The pinctrl properties should be on the device directly and not on the
slot sub-node.
Reported-by: NDoug Anderson <dianders@chromium.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NAndreas Faerber <afaerber@suse.de>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos5250-snow.dts

@@ -240,10 +240,8 @@
 	 */
 	mmc@12230000 {
 		status = "okay";
-		slot@0 {
-			pinctrl-names = "default";
-			pinctrl-0 = <&sd3_clk &sd3_cmd &sd3_bus4>;
-		};
+		pinctrl-names = "default";
+		pinctrl-0 = <&sd3_clk &sd3_cmd &sd3_bus4>;
 	};
 
 	i2c@12CD0000 {