[MTD] [NAND] pasemi_nand driver

Plumbing for NAND connected via localbus on PA Semi PWRficient-based
boards.

From: Egor Martovetsky <egor@pasemi.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>