mtd: devices: added the 16MiB winbond device

Added a 16MiB winbond devce to the device list
erase size = 64KiB and number of blocks = 256.

Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>