flashchips: Add IS25LP256 and IS25WP256

Tested IS25LP256 using Raspberry Pi and Dediprog SF600 programmers.
Tested IS25WP256 using Dediprog SF600.

Change-Id: Idf7a224abcde5f7935d9ef88309f78207de60a7a
Signed-off-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-on: https://review.coreboot.org/29306
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
2 files changed