scsi: ufs: Logical Unit (LU) command queue depth

Some of the UFS devices may support different number of commands
that can be queued per LU. At the current implementation,
SW configure each of the UFS devices LU's according to the
controller capability.

In this patch we read the queue depth available per LU and update
the LU's SW structure.

Change-Id: I1f2d1bb66f44f08bb24edc2d439b71ea99b358cb
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>