scsi: ufs-qcom: implement ufs dbg_register_dump cb

Errors such as UIC errors, illegal OCS values, and others may require
information kept in non standard UFS registers but controller debug
registers.
Implementing dbg_register_dump cb gives access to such register while
debugging those issues.

Change-Id: I259c3d691b95f72ea62ed162492f9081d472de80
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>