Fix JFFS2 support for legacy NAND driver.

Some more NAND cleanup and small fixes.
diff --git a/include/configs/NC650.h b/include/configs/NC650.h
index 371ea17..3c59df4 100644
--- a/include/configs/NC650.h
+++ b/include/configs/NC650.h
@@ -217,6 +217,8 @@
 /*
  * NAND flash support
  */
+#define CFG_NAND_LEGACY
+
 #define CFG_MAX_NAND_DEVICE	1
 #define NAND_ChipID_UNKNOWN	0x00
 #define SECTORSIZE		512