Match the i386 behaviour and only care about bus_clock if we don't have the tables from acpi.  This way we don't have to have knowledge of the cpu model to do speedstep in the acpi case.
Match the i386 behaviour and only care about bus_clock if we
don't have the tables from acpi.  This way we don't have
to have knowledge of the cpu model to do speedstep in the acpi case.

ok kettenis@

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