drm/bridge: tda998x: Add support for DRM_BRIDGE_ATTACH_NO_CONNECTOR

drm/bridge: tda998x: Add support for DRM_BRIDGE_ATTACH_NO_CONNECTOR

Add support for the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag to allow display
controller drivers to create their own connectors. This modernizes the
driver to work with the current DRM bridge framework.

The implementation includes:
- Refactoring detection and EDID reading into bridge-usable helpers
- Adding bridge operations: edid_read, detect, hpd_enable, hpd_disable
- Setting appropriate bridge ops (DRM_BRIDGE_OP_EDID, DRM_BRIDGE_OP_DETECT,
  DRM_BRIDGE_OP_HPD) and connector type (HDMIA)
- Skipping connector creation when DRM_BRIDGE_ATTACH_NO_CONNECTOR is set
- Handling conditional connector cleanup in bridge_detach

The driver maintains backward compatibility by continuing to create its
own connector when the flag is not set.

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-v5-24-5a44d2aa3f6f@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>