BFIN: Fix gen_nand probe structures contents

These two platforms didn't properly fill nr_chips in gen_nand 
registration and therefore depended on gen_nand bug fixed by by commit
81cbb0b17796d81cbd92defe113cf2a7c7a21fbb ("mtd: gen_nand: fix support for
multiple chips")

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

arch/blackfin/mach-bf537/boards/stamp.c

@@ -400,6 +400,7 @@ static int bfin_plat_nand_dev_ready(struct mtd_info *mtd)
 
 static struct platform_nand_data bfin_plat_nand_data = {
 	.chip = {
+		.nr_chips = 1,
 		.chip_delay = 30,
 #ifdef CONFIG_MTD_PARTITIONS
 		.part_probe_types = part_probes,

arch/blackfin/mach-bf561/boards/acvilon.c

@@ -284,6 +284,7 @@ static int bfin_plat_nand_dev_ready(struct mtd_info *mtd)
 
 static struct platform_nand_data bfin_plat_nand_data = {
 	.chip = {
+		 .nr_chips = 1,
 		 .chip_delay = 30,
 #ifdef CONFIG_MTD_PARTITIONS
 		 .part_probe_types = part_probes,