scsi: ufs: disable aggressive clock gating

Power management with UFS host and device has multiple issues. Until
all those issues are fixed, disable the aggressive clock gating mechanism.

Change-Id: I2ab9b3b264ac526d4d7dd3ed0c9eedf4b4db6d8e
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>