defconfigs: remove CONFIG_MTD_NAND_VERIFY_WRITE

CONFIG_MTD_NAND_VERIFY_WRITE was killed recently, so remove it from
defconfigs as well.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>