davinci: Add NAND flash support for DA850/OMAP-L138

This patch adds platform data for the 512MB NAND Flash
found on DA850/OMAP-L138 EVM. Currently it supports
only 1-bit ECC.

Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>