drm/amd/display: Avoid force minimal transaction in case of surface_count equal to 0

[why]
Call commit_minimal_transition_state wrongly in case of surface_count
equal to 0.

[how]
Add a condition to filter case of surface_count equal to 0.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: JeromeHong <jerome.hong@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>