msm: kgsl: Count inter-frame power collapses

It is useful to know how many times inter-frame
power collapse happens. Enable the IFPC counters
and add a trace and a sysfs node to allow tracking
the count.

Change-Id: I670126d9e61f3831b6c60b895ba373a3be98a029
Signed-off-by: Kyle Piefer <kpiefer@codeaurora.org>
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>