mtd: nand: Add WATCHDOG_RESET() in nanddev_mtd_erase()

In case of big area erased on nand, watchdog timeout may occurs.
To fix that, add WATCHDOG_RESET() in nanddev_mtd_erase() to ensure that
watchdog is reset.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c
index 219efdc..090834a 100644
--- a/drivers/mtd/nand/core.c
+++ b/drivers/mtd/nand/core.c
@@ -10,6 +10,7 @@
 #define pr_fmt(fmt)	"nand: " fmt
 
 #include <common.h>
+#include <watchdog.h>
 #ifndef __UBOOT__
 #include <linux/compat.h>
 #include <linux/module.h>
@@ -172,6 +173,7 @@
 	nanddev_offs_to_pos(nand, einfo->addr, &pos);
 	nanddev_offs_to_pos(nand, einfo->addr + einfo->len - 1, &last);
 	while (nanddev_pos_cmp(&pos, &last) <= 0) {
+		WATCHDOG_RESET();
 		ret = nanddev_erase(nand, &pos);
 		if (ret) {
 			einfo->fail_addr = nanddev_pos_to_offs(nand, &pos);