cpufreq: interactive governor: go to intermediate hi speed before max

* Add attribute hispeed_freq, which defaults to max.

* Rename go_maxspeed_load to go_hispeed_load.

* If hit go_hispeed_load and at min speed, go to hispeed_freq;
  if hit go_hispeed_load and already above min speed go to max
  speed.

Change-Id: I1050dec5f013fc1177387352ba787a7e1c68703e
Signed-off-by: Todd Poynor <toddpoynor@google.com>