staging:mt29f_spinand: MT29F2G failing as only 16 bits used for addressing.

For NAND flash chips with more than 1Gbit (e.g. MT29F2G) more than 16 bits
are necessary to address the correct page.

Signed-off-by: Palle Christensen <palle.christensen@microsemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>