omap_gpmc_decode_bch() is defined in its user rather than properly in a
header file. Add a header file to be included by both its user and the
file implementing it.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

So that it does not collide with our generic decode_bch function.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Bit errors in the ECC itself are not beeing taken into account.
In this cases the number of detected errors != number of corrected errors and
chien search returns an error.
This patch adds detection of bit errors in the ECC.

Signed-off-by: Steve Schefter <steve@scheftech.com>
Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

This patch adds BCH ecc support to the omap nand driver. The BCH
error correction allows for up to 8 bit error correction. It is
also needed for booting from nand on omap4.

This is based on code from Sukumar Ghorai <s-ghorai@ti.com>:

[PATCH] omap3: nand: bch ecc support added

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>