ARM: dts: fix duplicated build target and alphabetical sort out for exynos

Commit db5b0ae0 ("Merge tag 'dt' of git://git.kernel.org/.../arm-soc")
causes a duplicated build target.  This patch fixes it and sorts out the
build target alphabetically so that we can recognize something wrong
easily.

Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arm/boot/dts/Makefile

@@ -42,11 +42,10 @@ dtb-$(CONFIG_ARCH_DOVE) += dove-cm-a510.dtb \
 dtb-$(CONFIG_ARCH_EXYNOS) += exynos4210-origen.dtb \
 	exynos4210-smdkv310.dtb \
 	exynos4210-trats.dtb \
-	exynos5250-smdk5250.dtb \
-	exynos5440-ssdk5440.dtb \
 	exynos4412-smdk4412.dtb \
 	exynos5250-smdk5250.dtb \
-	exynos5250-snow.dtb
+	exynos5250-snow.dtb \
+	exynos5440-ssdk5440.dtb
 dtb-$(CONFIG_ARCH_HIGHBANK) += highbank.dtb \
 	ecx-2000.dtb
 dtb-$(CONFIG_ARCH_INTEGRATOR) += integratorap.dtb \