scsi: ufs: disable ah8 during suspend and enable it on resume

Auto hibern8 is useful during active requests for efficient power
savings. Since we are anyway in suspend path, disable auto
hibern8 until a successful resume. This prevents unnecessary hibern8
enter/exit during the suspend/resume path.

Change-Id: Ie5a76dddd662e67ae8ce6e6f37f437ff4665b066
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
[cang@codeaurora.org: resolved trivial merge conflicts]
Signed-off-by: Can Guo <cang@codeaurora.org>