msm: acpuclock-7627: Avoid AXI freq. change while going into power collapse

There is no reason to change the AXI freq. while going into the PC
since the same AXI frequency is maintained by vote while coming
out of the PC. If the suspend power collapse happens from the
arch_idle path then we would see the sleeping calls while atomic
warning due to mutex being held in the clk_set_rate calls.

Change-Id: I5343c7ea6927c236046d62e94791462cdd8eccf6
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>