drm/connector: Warn if a connector is registered/added incorrectly

drm/connector: Warn if a connector is registered/added incorrectly

All the drivers should be converted now to use
drm_connector_dynamic_init() for MST connectors, hence
drm_connector_dynamic_register()->drm_connector_add() can WARN now if
this was not the case (for instance if a driver inited an MST connector
with one of the drm_connector_init*() functions incorrectly).

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241211230328.4012496-9-imre.deak@intel.com