initscripts package is being slowly removed so fedora-autorelabel
utility and systemd unit files need a new home.
At the same time, "fedora-" prefix is changed to general "selinux-".
/lib/systemd/fedora-autorelabel -> /usr/libexec/selinux/selinux-autorelabel
fedora-autorelabel.service -> selinux-autorelabel.service
fedora-autorelabel-mark.service -> selinux-autorelabel-mark.service
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1328825
