The "kyua about" command assumes these files exist causing tests
supplied devel/kyua to fail.
Fix a bug defining the default KYUA_DOCDIR so the installed files can be
found.
Reported by: jenkins tests
Reviewed by: lwhsu
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24187
Having kyua in the base system will simplify automated testing in CI and
eliminates bootstrapping issues on new platforms.
The build of kyua is controlled by WITH(OUT)_TESTS_SUPPORT.
Reviewed by: emaste
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24103