msm: kgsl: Log register offset when fenced write fails

Currently it prints the enum, which isn't very helpful.
Log the register offset instead for better readability.

Change-Id: I6ba3f3363c67cdc84f82fdb346af03e0ca049355
Signed-off-by: Harshdeep Dhatt <hdhatt@codeaurora.org>
Signed-off-by: Urvashi Agrawal <urvaagra@codeaurora.org>