Bump max number of physical segments.  Machines in the wild seem to have reached this limit.
Bump max number of physical segments.  Machines in the wild
seem to have reached this limit.

ok marco@, looks ok ckuethe@

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