drm/tilcdc: Add support for DRM_BRIDGE_ATTACH_NO_CONNECTOR

drm/tilcdc: Add support for DRM_BRIDGE_ATTACH_NO_CONNECTOR

Convert the driver to use the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag when
attaching bridges. This modernizes the driver by delegating connector
creation to the bridge subsystem through drm_bridge_connector_init()
instead of manually searching for connectors created by the bridge.

The custom tilcdc_encoder_find_connector() function is removed and
replaced with the standard drm_bridge_connector infrastructure, which
simplifies the code and aligns with current DRM bridge best practices.

This change is safe as there are now no in-tree devicetrees that
connect tilcdc to bridges which do not support the
DRM_BRIDGE_ATTACH_NO_CONNECTOR flag.

Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Kory Maincent (TI.com) <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20260123-feature_tilcdc-v5-25-5a44d2aa3f6f@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>