autosmp: use cpu frequency instead of load average
- less overhead for the system without the additional load calculation
  by autosmp,
- autosmp needs to work with cpu governor in giving adequate computing
  power to system and CPU governor should have the leading role in this
  task since it must respond earlier,
- since frequency is a function of CPU load determined by the CPU
  governor, autosmp becomes more consistent with the CPU governor when
  CPU frequency is used instead of independently calculating the load
  average,
- works in better sync with the CPU governor by giving the priority
  to increasing the frequency before rushing into hotplugging a core or
  dragging the system
- since autosmp follows the CPU governor it automatically adapts when
  governor is changed.