fdt_support: Use CONFIG_NR_DRAM_BANKS if necessary

If CONFIG_NR_DRAM_BANKS is bigger than the default
value (4) define MEMORY_BANKS_MAX as CONFIG_NR_DRAM_BANKS.

Fixes: 2a1f4f1758b5 ("Revert "fdt_support: Use CONFIG_NR_DRAM_BANKS if defined"")
Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
diff --git a/common/fdt_support.c b/common/fdt_support.c
index 34d2bd5..d84f5db 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -409,7 +409,11 @@
 	return p - (char *)buf;
 }
 
+#if CONFIG_NR_DRAM_BANKS > 4
+#define MEMORY_BANKS_MAX CONFIG_NR_DRAM_BANKS
+#else
 #define MEMORY_BANKS_MAX 4
+#endif
 int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks)
 {
 	int err, nodeoffset;