drm/nouveau: implement missing DCB connector types; gracefully handle unknown connectors

drm/nouveau: implement missing DCB connector types; gracefully handle unknown connectors

* Implement missing DCB connectors in uconn.c previously defined in conn.h.
* Replace kernel WARN_ON macro with printk message to more gracefully signify
  an unknown connector was encountered.

With this patch, unknown connectors are explicitly marked with value 0
(DCB_CONNECTOR_VGA) to match the tested current behavior. Although 0xff
(DCB_CONNECTOR_NONE) may be more suitable, I don't want to introduce a
breaking change.

Fixes: 8b7d92cad953 ("drm/nouveau/kms/nv50-: create connectors based on nvkm info")
Link: https://download.nvidia.com/open-gpu-doc/DCB/1/DCB-4.0-Specification.html#_connector_table_entry
Signed-off-by: Alex Ramírez <lxrmrz732@rocketmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[Lyude: Remove unneeded parenthesis around nvkm_warn()]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20251213005327.9495-3-lxrmrz732@gmail.com