cpuboost: Add hotplug boosting

If we decide to hotplug a core then we are making a strong
statement that we think that the system load is high.  Let's
have faith in our hotplug driver(s) and boost the cpufreq
when we are hotplugging cores.

Change-Id: Id35bae6c27c39097c7aca70eebf1498ed0c3dfdc
Merge "cpuboost: Add hotplug boosting" into cm-11.0