Thermal: Add thermal events tracing (ftrace)

Thermal: Add thermal events tracing (ftrace)

Following two events in thermal framework are traced:
 - Call to handle_thermal_trip (thermal_zone_device name and temperature
   will be printed)
 - Call to thermal_cdev_update (thermal_cooling_device name and updated
   cooling state value will be printed)

Bug 1050412

Change-Id: If7e685ce26455820408d694fa720105ecae15469
Signed-off-by: Timo Alho <talho@nvidia.com>
Reviewed-on: http://git-master/r/207010
Reviewed-by: Juha Tukkinen <jtukkinen@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Peter De Schrijver <pdeschrijver@nvidia.com>