omap3/omap_gpmc.h: add ooblayout for BCH8 as in kernel

This patch adds BCH8 ooblayout for NAND as provided by
0e618ef0a6a33cf7ef96c2c824402088dd8ef48c in linux kernel. This Layout is
currently only provided for 64 byte OOB.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Cc: Tom Rini <trini@ti.com>
Cc: Ilya Yanok <ilya.yanok@cogentembedded.com>
Cc: Scott Wood <scottwood@freescale.com>
Reviewed-by: Tom Rini <trini@ti.com>