* sun3 does not call timer_routine() but open-codes it
except for the profile_tick() call that appears to
be unintentionally missing.
* sun3x has a commented-out timer irq handler but no
functional timer tick I could find.
Change both to calling the new legacy_timer_tick here,
which includes the call to profile_tick() but does not
fix sun3x as that is still commented out.