msm: kgsl: Count user and kernel performance counters seperately

Rather than just storing if the performance counter was referenced by the
kernel in a flag, keep track of user space and kernel space references
seperately.  This allows finer grained manipulations on the performance
counters (ie when allowed to be released).  This is needed to be able to
turn off certain performance counters when fault tolerance is disabled
at runtime.

Change-Id: I7b5593459e64557dabd594aeb6532a0c9af6a9c5
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>