Exynos: Split 5250 and 5420 memory bank configuration

Since snow has a different memory configuration than peach, split the
configuration between the 5250 and 5420. Exynos 5420 supports runtime
memory configuration detection, and can make the determination between 4
and 7 banks at runtime.

Include the bank size with the number of banks for context to make the
number of banks meaningful.

Signed-off-by: Michael Pratt <mpratt@chromium.org>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/include/configs/exynos5250-dt.h b/include/configs/exynos5250-dt.h
index 3982010..74e72a5 100644
--- a/include/configs/exynos5250-dt.h
+++ b/include/configs/exynos5250-dt.h
@@ -65,4 +65,9 @@
 #define LCD_YRES			1600
 #define LCD_BPP			LCD_COLOR16
 #endif
+
+/* DRAM Memory Banks */
+#define CONFIG_NR_DRAM_BANKS	8
+#define SDRAM_BANK_SIZE		(256UL << 20UL)	/* 256 MB */
+
 #endif  /* __CONFIG_5250_H */