arm/kirkwood/nand: allow forced disabling for subpage writes

Make it configurable to disable subpage writes like the DaVinci NAND
driver already does.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
cc: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Prafulla Wadaskar <prafulla@marvell.com>
cc: Scott Wood <scottwood@freescale.com>

drivers/mtd/nand/kirkwood_nand.c

@@ -58,6 +58,9 @@ void kw_nand_select_chip(struct mtd_info *mtd, int chip)
 int board_nand_init(struct nand_chip *nand)
 {
 	nand->options = NAND_COPYBACK | NAND_CACHEPRG | NAND_NO_PADDING;
+#if defined(CONFIG_SYS_NAND_NO_SUBPAGE_WRITE)
+	nand->options |= NAND_NO_SUBPAGE_WRITE;
+#endif
 #if defined(CONFIG_NAND_ECC_BCH)
 	nand->ecc.mode = NAND_ECC_SOFT_BCH;
 #else