drm/i915: Don't init eDP if we can't find a fixed mode

drm/i915: Don't init eDP if we can't find a fixed mode

In the unlikely case of not finding a fixed mode don't register
the eDP connector. I think there are some places where we'd oops
if we didn't have a fixed mode for eDP so presumable this doesn't
typically happen. But better safe than sorry.

Also pimp the debugs with the encoder id+name. I think dumping
the encoder rather than the connector provides more information
here (eg. to match against the port information in the VBT).

We can also drop the extra check from intel_edp_add_properties().

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220912111814.17466-14-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>