[ARM] 5284/1: pxa: cm-x255: add NOR and NAND flash support

This patch adds support for NOR and NAND flashes on CM-X255.
The NAND flash support uses not yet merged GPIO NAND driver.

Signed-off-by: Russ Dill <russ.dill@gmail.com>
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>