FROMGIT: scsi: ufs: ufs-mediatek: Fix power down spec violation

As per spec, e.g. JESD220E chapter 7.2, while powering off the UFS device,
RST_N signal should be between VSS(Ground) and VCCQ/VCCQ2. The power down
sequence after fixing:

Power down:

 1. Assert RST_N low

 2. Turn-off VCC

 3. Turn-off VCCQ/VCCQ2

Bug: 188004633
Change-Id: I902935f5bb987d1cf3b80170cc9eb866de44bc13
(cherry picked from commit c625b80b
 https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git scsi-fixes)
Link: https://lore.kernel.org/r/1620813706-25331-1-git-send-email-peter.wang@mediatek.com


Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>