scsi: ufs: add time profiling support

This patch adds the profiling support for some of the time critical
operations like hibern8 enter/exit, clock gating & clock scaling.

Reviewed-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>