devfreq: Re-enable simple_ondemand. Also fix simple_ondemand crashing

(cherry picked from commit 1100a7df63ae81eb4deb19f265ba5465e13e636f)

(cherry picked from commit fde539cbaddf9328bdb977f455e844e8ba09483b)

Change-Id: Ic380427b719c319dcdc9e4bd9e3a45d50972b38c

(cherry picked from commit 9ad93e3da55969f179e65fb66bf2c5209a60cb25)