mtd: nand: pxa3xx: add support for 2KB 8-bit flash

Add support for 2KB page 8-bit ECC strength flash layout

Signed-off-by: Victor Axelrod <victora@marvell.com>
Reviewed-by: Igal Liberman <igall@marvell.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Stefan Roese <sr@denx.de>