disp: msm: dp: add timeout state for simulated AUX transfers

Add a new state to indicate timeout failures in simulation mode.
This can be used by test scripts to trigger a retry of the
session.

Change-Id: I9e250ba7d42fcb318698d8456b3acc5b55081abc
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>