kgsl: do not vmap/memset to zero-out pages

b/18402205 External reports: Video playback failing on Flo after upgrade to
	   Lollipop

Change-Id: I358328ba2bd543d77e4218f32b0695c2f6f6e6c9
Signed-off-by: Iliyan Malchev <malchev@google.com>
soc: qcom: rq_stats: Pass correct cpu id to update_average_load function

Pass correct cpu number to update_average_load function
from cpufreq_transition_handler function. Also avoid div by zero
condition in update_average_load function.

CRs-Fixed: 708310
Change-Id: I4ec3e54b92c760ac5fa910542524fdfe919f55e9
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
sched: Fix inaccurate accounting for real-time task

It is possible that rq->clock_task was not updated in put_prev_task()
in which case we can potentially overcharge a real-time task for time
it did not run. This is because clock_task could be stale and not
represent the exact time real-time task started running.

Fix this by forcing update of rq->clock_task when real-time task
starts running.

Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>