[MTD] [NAND] davinci_nand driver

This is a device driver for the NAND flash controller found on the various
DaVinci family chips.  It handles up to four SoC chipselects, and some
flavors of secondary chipselect (e.g.  based on upper bits of the address
bus) as used with some multichip packages.  (Including the 2 GiB chips
used on some TI devel boards.)

The 1-bit ECC hardware is supported (3 bytes ECC per 512 bytes data); but
not yet the newer 4-bit ECC (10 bytes ECC per 512 bytes data), as
available on chips like the DM355 or OMAP-L137 and needed with the more
error-prone MLC NAND chips.

This is a cleaned-up version of code that's been in use for several years
now; sanity checked with the new drivers/mtd/tests.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>