drivers/spi: Add support for adesto SPI flash parts

Adds support for the following Adesto Technologies
SPI Flash parts.

AT25DF081
AT25DF321
AT25DF641

It has been tested on an Orion VPX7654 board populated
with an AT25DF321A part. The "08" and "64" densities have not
been tested.

These parts are the successors of the Atmel AT26DF line that
was spun out or purchased by Adesto.

In this patch, adesto.c is identical to winbond.c with part
entries for the Adesto parts. The datasheet for the AT25DF parts
includes a "100MHz" programming command in addition to the "85MHz"
command that is currently used but this patch does not add support
for that enhanced programming mode.

Change-Id: If82d075fd9000030480c412c645dcae2c8bb7439
Signed-off-by: Christopher Douglass <cdouglass.orion@gmail.com>
Reviewed-on: http://review.coreboot.org/5225
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
5 files changed