msm: kgsl: Correct adjustment calculation for LM on A640

The adjustment for DCVS due to LM is being calculated
incorrectly. The weighting of the first throttle count
should be 15%.

Change-Id: I5c8cae6900dee36e62251c9f5c3d6b4227b1e9ee
Signed-off-by: Kyle Piefer <kpiefer@codeaurora.org>