ARM: dts: Update Exynos DT files with generic compatible strings

Add generic compatible strings to the respective board DT files.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/boot/dts/exynos5420-smdk5420.dts b/arch/arm/boot/dts/exynos5420-smdk5420.dts
index fb5a1e2..aa215bd 100644
--- a/arch/arm/boot/dts/exynos5420-smdk5420.dts
+++ b/arch/arm/boot/dts/exynos5420-smdk5420.dts
@@ -14,7 +14,7 @@
 
 / {
 	model = "Samsung SMDK5420 board based on EXYNOS5420";
-	compatible = "samsung,smdk5420", "samsung,exynos5420";
+	compatible = "samsung,smdk5420", "samsung,exynos5420", "samsung,exynos5";
 
 	memory {
 		reg = <0x20000000 0x80000000>;