scsi: ufs-debugfs: add error state

This change adds support to allow user space query if low level UFS driver
has encountered any error or not, this state can be read/cleared via
debugfs.

Change-Id: I867a4621315108aff17be852cfaadcfa945566a7
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>