ARM: EXYNOS: add dts files to dtbs target

Add the currently in-tree device tree sources to the dtbs target.
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/Makefile.boot

    zreladdr-y	+= 0x40008000
 params_phys-y	:= 0x40000100
+
+dtb-$(CONFIG_MACH_EXYNOS4_DT) += exynos4210-origen.dtb exynos4210-smdkv310.dtb
+dtb-$(CONFIG_MACH_EXYNOS5_DT) += exynos5250-smdk5250.dtb