msm: kgsl: use correct load bit value for rbbm perf counter

The load bit value used for RBBM_PERFCTR_RBBM_0 is incorrect.
Correct the load bit so that the saved value is loaded into the
desired counter.

Change-Id: Id0c8cb65061ce061ae342f62576ea020553e0f80
Signed-off-by: Puranam V G Tejaswi <pvgtejas@codeaurora.org>