Revert the 'performance' setting to 'NONE' from C2. C2 has issues with
USB in places, as well as having the potential for reducing
performance. Since this is used even when powerd isn't enabled, these
two problems can cause on servers. Supermicro X9 motherboards, for
example, have problems with the virtual IPMI USB keyboards and mice
attaching and detaching repeatedly. Since there are issues on some
CPUs with C2, fail safe by defaulting to not altering it.

MFC After: 3 days