msm_thermal: New thermal driver

The code in the HTC dump is completely broken.  Rewritten to work
and to support more aggressive lower-end throttling and configurability.

There are three throttling tiers defined at 60C, 70C, 80C where we
throttling to 1.3GHz, 900Mhz, 380MHz.  The goal is to spead more time
at 1.3 and stay at a mid temp than shoot straight up to the 900Mhz
throttling.  Added the top level to add a safety net for going too hot.

All the parameters are exposed in /sys/module/msm_thermal/parameters.