Update the NAND code to match Linux v4.1.  The previous sync was
from Linux v3.15 in commit 4e67c571.

CONFIG_SYS_NAND_RESET_CNT is removed, as the upstream Linux code now
has its own timeout.  Plus, CONFIG_SYS_NAND_RESET_CNT was undocumented
and not selected by any board.
Signed-off-by: NScott Wood <scottwood@freescale.com>

Signed-off-by: NWolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: NTom Rini <trini@ti.com>

Commit dfe64e2c:

    mtd: resync with Linux-3.7.1

broke the docg4 driver.  Specifically:
 - some of the prototypes of the ecc methods changed
 - the NAND_NO_AUTOINCR flag was removed
 - the ecc.strength element was added.

This patch fixes these.  Tested on the docg4 on my palmtre680 board.
Signed-off-by: NMike Dunn <mikedunn@newsguy.com>

This patch adds a driver for the diskonchip G4 nand flash device.  It is based
on the driver from the linux kernel.

This also includes a separate SPL driver.  A separate SPL driver is used because
the device operates in a different mode (reliable mode) when loading a boot
image, and also because the storage format of the boot image is different from
normal data (pages are stored redundantly).  The SPL driver basically mimics how
a typical IPL reads data from the device.  The special operating mode and
storage format are used to compensate for the fact that the IPL does not contain
the BCH ecc decoding algorithm (due to size constraints).  Although the u-boot
SPL *could* use ecc, it operates like an IPL for the sake of simplicity and
uniformity, since the IPL and SPL share the task of loading the u-boot image.
As a side benefit, the SPL driver is very small.

[port from linux kernel 3.4 commit 570469f3bde7f71cc1ece07a18d54a05b6a8775d]
Signed-off-by: NMike Dunn <mikedunn@newsguy.com>