we trust the calibrated pentium_mhz more, so don't overwrite it unless we know the cpu speed has changed.  fixes pr3814 from mark pecaut.
we trust the calibrated pentium_mhz more, so don't overwrite it unless
we know the cpu speed has changed.  fixes pr3814 from mark pecaut.

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