drm/nouveau: use dcb connector table for creating drm connectors

This makes this code common to both the nv04 and nv50 paths.

For the moment, we keep the previous behaviour with HDMI/eDP connectors
and report them as DVI-D/DP instead.  This will be fixed once the rest
of the code has been fixed to deal with those types.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>