NAND: add more watchdog resets

Poke the watchdog in a variety of looping constructs, which could take
a long time to complete.

Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
index 8b4f738..5a6f7ae 100644
--- a/drivers/mtd/nand/nand_util.c
+++ b/drivers/mtd/nand/nand_util.c
@@ -542,6 +542,8 @@
 
 			pages = write_size / pagesize_oob;
 			for (page = 0; page < pages; page++) {
+				WATCHDOG_RESET();
+
 				ops.datbuf = p_buffer;
 				ops.oobbuf = ops.datbuf + pagesize;