Copy over some recent commits from ix(4)..
Copy over some recent commits from ix(4)..

- remove pointless timeout_del/add dance in the interrupt handler
- don't try to update the link status every second
- Gather full statistics only when EM_DEBUG is defined

ok mikeb@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars