mtd: nand: davinci: add OF support for davinci nand controller

add OF support for the davinci nand controller.

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>