drm/amd/display: add pipe topology update log

Given an issue with pipe topology transition. It is very hard to tell
the before and after pipe topology without a pipe topology logging. The
change adds such logging to help with visualizing the issue.

Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>