Fix segfault when running `flashrom -L`

The raiden_debug programmer is of type USB. However, it does not set the
field `devs.dev`, which will result in a segfault when trying to print
the devices of the non-existing table.

Fix that by replacing `devs.note` with `devs.dev` and adding an empty
device table. Since Device IDs are not used to match programmers,
nothing could be added to the table.

TEST=Running `flashrom -L` no longer segfaults and returns normally.

Change-Id: Ie4171a11384c34abb102d1aadf86aa1b8829fc04
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/39826


Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>