drm/msm/dp: cleanup log messages in mst layer

Introduce a new macro definition for critical log messages
and use this new macro for topology state related message logs.

Change-Id: I68c8c981ae781c490446449cd0ef80f97ae90adf
Signed-off-by: Govinda Rajulu Chenna <gchenna@codeaurora.org>
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>