drm/nouveau: Use atomic VCPI helpers for MST
Currently, nouveau uses the yolo method of setting up MST displays: it uses the old VCPI helpers (drm_dp_find_vcpi_slots()) for computing the display configuration. These helpers don't take care to make sure they take a reference to the mstb port that they're checking, and additionally don't actually check whether or not the topology still has enough bandwidth to provide the VCPI tokens required. So, drop usage of the old helpers and move entirely over to the atomic helpers. Changes since v6: * Cleanup atomic check logic and remove a bunch of unneeded checks - danvet Changes since v5: * Update nv50_msto_atomic_check() and nv50_mstc_atomic_check() to the new requirements for drm_dp_atomic_find_vcpi_slots() and drm_dp_atomic_release_vcpi_slots() Signed-off-by:Lyude Paul <lyude@redhat.com> Reviewed-by: