When migrating the firmware to be installed as plain firmware files
to /boot/firmware the iwm8000C firmware lost its "fw" suffix that
iwm(4) expects.
The follow-up change to defaults/loader.conf is also consistently
missing the "fw".
Fix both places, and add the wrongly spelt version to ObsoleteFiles.inc
(entirely untested).
PR: 291403
Reported by: Augustin Hoffmann (avgwst tutanota.de)
Fixes: af0a81b647
Fixes: a0f06dfb0d
MFC after: 3 days
Bjoern A. Zeeb
f0ea859229