msm: kgsl: Briefly turn off interrupts to create a time domain mapping

This code is attempting to creating a mapping between the GPU time
domain (alwayson counter) and the CPU time domain (local_clock) by
sampling both values as close together as possible. This is useful
for many types of debugging and profiling. In order to make this
mapping as accurate as possible, we must turn off interrupts to
avoid running interrupt handlers between the two samples.

Change-Id: I5a6eb0af93aac44662d29f22006c14ed7ed38c76
Signed-off-by: Kevin Matlage <kmatlage@codeaurora.org>