mtd: pxa3xx_nand: add a default chunk size

When keeping the configuration set by the bootloader (by using
the marvell,nand-keep-config property), the pxa3xx_nand_detect_config()
function is called and set the chunk size to 512 as a default value if
NDCR_PAGE_SZ is not set.

In the other case, when not keeping the bootloader configuration, no
chunk size is set. Fix this by adding a default chunk size of 512.

Fixes: 70ed8523 ("mtd: nand: pxa3xx: Introduce multiple page I/O
support")
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/pxa3xx_nand.c

@@ -1476,6 +1476,9 @@ static int pxa3xx_nand_scan(struct mtd_info *mtd)
 	if (pdata->keep_config && !pxa3xx_nand_detect_config(info))
 		goto KEEP_CONFIG;
 
+	/* Set a default chunk size */
+	info->chunk_size = 512;
+
 	ret = pxa3xx_nand_sensing(info);
 	if (ret) {
 		dev_info(&info->pdev->dev, "There is no chip on cs %d!\n",