scsi: ufs-qti: Enable block layer runtime PM for well-known logical units

Block layer RPM is enabled for the genernal UFS SCSI devices when they are
probed by their driver. However block layer RPM is not enabled for UFS
well-known SCSI devices.

As UFS SCSI devices have their corresponding BSG char devices, accessing
a BSG char device via IOCTL may send requests to its corresponding SCSI
device through its request queue. If BSG IOCTL sends a request to a
well-known SCSI device when hba is not runtime active, due to block layer
RPM is not eanbled for the well-known SCSI devices, hba, which is at the
top of a scsi device's parent chain, shall not be resumed, then unexpected
error would happen.

This change enables block layer RPM for the well-known SCSI devices, so
that block layer can handle RPM for the well-known SCSI devices just like
for the general SCSI devices.

Change-Id: Ie4c5c4876f8500c285166a5f7be87a2157a12df3
Signed-off-by: Can Guo <cang@codeaurora.org>