msm: kgsl: Keep the GPU from going into a slumber after a touch event

If the GPU is on the tail end of the nap period when a new touch event
occurs the system could go into slumber before the first render which
increases the startup latency. If a touch event occurs while in nap
just kick the idle timer back out to the interval timeout - this should
keep the system from transitioning to the lower power state only to
come right back up.

Change-Id: Ic0dedbad07cac877d0a71c69516b7c01841be1bd
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>