Currently the damon selftests are not built with the rest of the
selftests. We add damon to the list of targets.

Fixes: b348eb7a ("mm/damon: add user space selftests")
Reviewed-by: NSeongJae Park <sj@kernel.org>
Signed-off-by: NYuanchu Xie <yuanchu@google.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NShuah Khan <skhan@linuxfoundation.org>