msm: kgsl: Save/restore performance counters across GPU power collapse

Physical performance counters are reset on GPU power collapse.
Save the values of the performance counters when the GPU goes to
power collapse and restore them on restart.

Change-Id: I63bec7b20e7fe516bbac4901cac0af3a1c1f4959
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>
msm: kgsl: Get CP_RPTR from register instead of shadow memory

Sometimes the RPTR shadow memory is unreliable causing timeouts
in adreno_idle().  Read it directly from the register instead.

Change-Id: Icae7521edd9723610c41f320c6a5c99f57bec7f5
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
msm: kgsl: Allow GPU start to run in a high priority queue

The GPU start sequence needs to run with low latency when coming
out of slumber for the first draw command. For those cases allow the
start function to be queued into a high priority workqueue to reduce
the chance of it getting scheduled out.

Change-Id: Ic0dedbada7ef4d63b54e826862fbefdfb71a092a
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>