sched: Introduce new workload differentiation

This is a key feature that helps with getting an appropriate
frequency response whenever a new workload starts. Start
reporting load corresponding to new tasks to cpufreq.

Change-Id: Ifc7d03579f20ed4dd6d04d2af12c21fa1833f62f
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>