davinci: Add NAND support for DA830/OMAP-L137 EVM platform

Add support for NAND flash parts on the DA830/OMAP-L137 EVM
User Interface board.  This includes overriding the default
bad block tables used by the davinci_nand driver.

Signed-off-by: David A. Griego <dgriego@mvista.com>
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>