scsi: ufs-qcom: add ICE debug prints

Add ICE debug prints for debugging purposes. These prints
will be shown as part of dumping registers during error handling.
Enabling can be controlled by debugfs.

Change-Id: I7d070cc8df099e6c526997d39973a3e1c161091b
Signed-off-by: Dov Levenglick <dovl@codeaurora.org>
[cang@codeaurora.org: Resolved trivial merge conflicts]
Signed-off-by: Can Guo <cang@codeaurora.org>