kunit: config: Enable KUNIT_DEBUGFS by default

kunit: config: Enable KUNIT_DEBUGFS by default

The KUNIT_DEBUGFS option is currently enabled based on the value of
KUNIT_ALL_TESTS, but it really doesn't have anything to do with the set of
enabled tests, so just enable it by default anyway. In particular, this
shouldn't be only visible if KUNIT_ALL_TESTS is set, which is quite
confusing.

Link: https://lore.kernel.org/r/20260425034155.53913-1-david@davidgow.net
Fixes: beaed42c427d ("kunit: default KUNIT_* fragments to KUNIT_ALL_TESTS")
Signed-off-by: David Gow <david@davidgow.net>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>