drm/i915: Associate ACPI connector nodes with connector entries (v2)

drm/i915: Associate ACPI connector nodes with connector entries (v2)

On Intel platforms we know that the ACPI connector device
node order will follow the order the driver (i915) decides.
The decision is made using the custom Intel ACPI OpRegion
(intel_opregion.c), though the driver does not actually know
that the values it sends to ACPI there are used for
associating a device node for the connectors, and assigning
address for them.

In reality that custom Intel ACPI OpRegion actually violates
ACPI specification (we supply dynamic information to objects
that are defined static, for example _ADR), however, it
makes assigning correct connector node for a connector entry
straightforward (it's one-on-one mapping).

Changes in v2 (Hans de goede):
- Take a reference on the fwnode which we assign to the connector,
  for ACPI nodes this is a no-op but in the future we may see
  software-fwnodes assigned to connectors which are ref-counted.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210817215201.795062-6-hdegoede@redhat.com