Make inteldrm_intr only do any work if we know for sure that interrupts are unmasked (so we aren't vt switched).
Make inteldrm_intr only do any work if we know for sure that interrupts
are unmasked (so we aren't vt switched).

Delay mutex aquisition until after we've make sure we have to worry
about interrupts.

The ironlake version of this behaves funny for guenther@ with
interaction on docking then restarting X. so has been left out of this
commit until I work out what the hell is going on.

Joint work with deraadt@ been in snaps for weeks

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