pxa3xx_nand: add new nand chip support

Support samsung 2GbX8 and 32GbX8 nand flash.
Support micron 4GbX8 and 4GbX16 nand flash.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>