msm_thermal: Add proper hotplug support (and make it fancy)

*Added a one-way sysfs switch to start msm_thermal
*Added a cpufreq notifier to properly throttle all CPUs (previously, only CPU0 was throttled, and then maxfreq was synced against CPU0 using a dirty hack in msm/cpufreq)
*Saves the minfreq independently for each CPU now
*Now runs in a high-priority workqueue

Signed-off-by: Sultanxda <sultanxda@gmail.com>
cpu_input_boost: Add cpufreq notifier and make it super fancy

*Everything is much cleaner
*Boosting is far less expensive now
*Now completely self-sufficient (doesn't require code to be added to other drivers)

Signed-off-by: Sultanxda <sultanxda@gmail.com>