mtd: nand: fix GET/SET_FEATURES address on 16-bit devices

[Brian Norris]

On Fri, Mar 21, 2014 at 04:05:10PM -0600, David Mosberger wrote:
> GET_FEATURES and SET_FEATURES also need byte-addressing on 16-bit devices.
> 
> Signed-off-by: David Mosberger <davidm at egauge.net>

Pushed to l2-mtd.git. Thanks!

Brian