Move SPI code out of board_enable.c where it started its life. The SPI

Move SPI code out of board_enable.c where it started its life. The SPI
chip finding and SPI chip accessor code is moved as well. This can be
split later if we feel like it.

The non-use of svn cp is intentional because the only history we'd have
to preserve are a few commits which were early prototypes of chip
identification code. For those who intend to look at that history, they
can look at board_enable.c revision 2853.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2857 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1