Makefile: Blacklist Digilent SPI (using USB) for DOS

Change-Id: I9a7dd5a2afcd12dd247e1f5534db61b79d77525e
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/33304
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
1 file changed