clk: msm: clock-cpu: Fix prepare_enable count for A53 pwr clock

CPUFreq driver does not use the a53_perf_clk clock and thus when there is a
CPU notifications to hotplug in/out cores there is an unbalanced reference
count for a53_pwr_clk is unbalanced (prepare).

Change-Id: I37b79e434c4fab58663c5f0e383cb83b9904cd31
Signed-off-by: Taniya Das <tdas@codeaurora.org>