arm:exynos: add common DTS file for exynos 4

This patch adds common dtsi file and config header for all
Exynos 4 based boards.

Patch additionaly adds board specific (weak) functions for
board_early_init_f and board_power_init functions.

Signed-off-by: Piotr Wilczek <p.wilczek@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/arch/arm/include/asm/arch-exynos/board.h b/arch/arm/include/asm/arch-exynos/board.h
index 243fb12..1b1cd0d 100644
--- a/arch/arm/include/asm/arch-exynos/board.h
+++ b/arch/arm/include/asm/arch-exynos/board.h
@@ -14,4 +14,16 @@
  */
 int exynos_init(void);
 
+/*
+ * Exynos board specific changes for
+ * board_early_init_f
+ */
+int exynos_early_init_f(void);
+
+/*
+ * Exynos board specific changes for
+ * board_power_init
+ */
+int exynos_power_init(void);
+
 #endif	/* EXYNOS_BOARD_H */