FROMGIT: scsi: ufs: Utilize Transfer Request List Completion Notification Register

By reading the UTP Transfer Request List Completion Notification Register,
which is added in UFSHCI Ver 3.0, SW can easily get the compeleted transfer
requests. Thus, SW can get rid of host lock, which is used to synchronize
the tr_doorbell and outstanding_reqs, on transfer requests dispatch and
completion paths. This can further benefit random read/write performance.

Link: https://lore.kernel.org/r/1621845419-14194-4-git-send-email-cang@codeaurora.org


Cc: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Co-developed-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Bug: 190637035
(cherry picked from commit 6f715172
git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git

 5.14/scsi-staging)
Change-Id: Ia76abaf40e3257c42b1e2b272b127552fbc79a81
Signed-off-by: Can Guo <cang@codeaurora.org>