FROMGIT: scsi: ufs: sysfs: Add sysfs entries for write booster

Adds unit, device, geometry descriptor sysfs entries.  Adds flags sysfs
entries for write booster.

Bug: 157166850
(cherry picked from commit c14e7adf3a6a8d0ce4d16f839f9737ad3481e239
https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git 5.8/scsi-queue)
Link: https://lore.kernel.org/r/98987ef17844292bd42c57613990a3a26c6de2b8.1587591527.git.asutoshd@codeaurora.org


Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Change-Id: Ia84b066bcfb0ebafe8f6e76129248ef4366c9054
Signed-off-by: Can Guo <cang@codeaurora.org>