scsi: ufs: Update L4 attributes on manual hibern8 exit in Cadence UFS.

Backup L4 attributes duirng manual hibern8 entry and restore the L4
attributes on manual hibern8 exit as per JESD220C.

Link: https://lore.kernel.org/r/1575606303-10917-1-git-send-email-sheebab@cadence.com


Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Sheeba B <sheebab@cadence.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>