drm/amd/display: add pipe lock during stream update

[why]
Stream update will adjust both info packets and stream params,
need to make sure all things are applied togather.

[how]
add pipe lock during stream update

Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>