scsi: ufs: Make clock scaling path PM Safe

When we set the governor of ufs devfreq to performance,
the hba's power status can still be runtime suspended.

So in these cases, when hibern8 exit is sent to device ,
since device has not yet resumed, we see hiber8 failure
with reason as power fatal error.

To Ensure hba's power runtime status is active before
command to device is sent , add pm_runtime_get/put_sync
in the clk scaling path to make it pm safe.

Change-Id: I7e87b4d8f2efff0e92bf34e30112dd29d55ceefd
Signed-off-by: Nitin Rawat <nitirawa@codeaurora.org>