msm: kgsl: Do not get active count on coresight start/stop

When coresight is started it is called from adreno_start
which should have the power and clocks enabled. Getting an active
count in coresight start path will cause the device mutex to be
released midway in adreno_start which can cause race conditions.
Similarly, there is no need to get active count when coresight is
being stopped.

Change-Id: I6a637bfcf02788e63f32acbcbb29e22df198efd0
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>