FBSD: Remove include directive for nonexistent file

In the bsd.kmod.mk world, this becomes a fatal error.

Reviewed-on: http://gerrit.openafs.org/5033
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 037f3251cd8fa318ad8320a061368efedc480c37)

Change-Id: If586761fce1254818c858d29ce6c31a5b8b13943
Reviewed-on: http://gerrit.openafs.org/10377
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>