Makefile: Disable libusb-dependent Raiden on DOS

DOS (DJGPP 6.1.0) has no USB support.

Change-Id: I36ee1edfb0e5b8d4e2b099c0f7f8aac64ed7884f
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/52474
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
1 file changed