nand, davinci: add special UBL ecc position

enable the RBL/UBL ECC layout through
CONFIG_NAND_6BYTES_OOB_FREE_10BYTES_ECC define

see for more info:
http://processors.wiki.ti.com/index.php/DM365_Nand_ECC_layout

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Tom Rini <trini@ti.com>
Cc: Scott Wood <scottwood@freescale.com>

drivers/mtd/nand/davinci_nand.c

@@ -266,6 +266,17 @@ static int nand_davinci_correct_data(struct mtd_info *mtd, u_char *dat,
 static struct nand_ecclayout nand_davinci_4bit_layout_oobfirst = {
 #if defined(CONFIG_SYS_NAND_PAGE_2K)
 	.eccbytes = 40,
+#ifdef CONFIG_NAND_6BYTES_OOB_FREE_10BYTES_ECC
+	.eccpos = {
+		6,   7,  8,  9, 10,	11, 12, 13, 14, 15,
+		22, 23, 24, 25, 26,	27, 28, 29, 30, 31,
+		38, 39, 40, 41, 42,	43, 44, 45, 46, 47,
+		54, 55, 56, 57, 58,	59, 60, 61, 62, 63,
+	},
+	.oobfree = {
+		{2, 4}, {16, 6}, {32, 6}, {48, 6},
+	},
+#else
 	.eccpos = {
 		24, 25, 26, 27, 28,
 		29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
@@ -276,6 +287,7 @@ static struct nand_ecclayout nand_davinci_4bit_layout_oobfirst = {
 	.oobfree = {
 		{.offset = 2, .length = 22, },
 	},
+#endif	/* #ifdef CONFIG_NAND_6BYTES_OOB_FREE_10BYTES_ECC */
 #elif defined(CONFIG_SYS_NAND_PAGE_4K)
 	.eccbytes = 80,
 	.eccpos = {