msm: kgsl: Add an input handler to power up the GPU on a touch event

On a device where the primary input is a touchscreen nobody is
surprised that touch events are often the catalyst for drawing
frames. If the GPU is in slumber we can get a jump on the action
by watching for touch events and turning the GPU on in anticipation
of a draw call. Register for events from all input drivers
returning EV_ABS events and queue a work task to power up the GPU
if it is currently in slumber.

Change-Id: Ic0dedbadbdc96ef9ddd78252ea65f8e1cdd00110
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: kgsl: Fix nice level for higher priority GPU start thread

Before, we were actually setting the lowest possible priority.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
msm: kgsl: Schedule adreno_start in a high priority workqueue

Better safe than sorry. Also, return early if we didn't set a _wake_timeout.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
msm: kgsl: Wake up GPU only for touch events

Register the KGSL input event handler only for
touch input events to make sure input event handler
is called only for touch input events.

Change-Id: I68938fbbf870bd3bce83cb057b504674753d6de8
Signed-off-by: Ananta Kishore K <akollipa@codeaurora.org>