drm/display: bridge-connector: handle CEC adapters

Implement necessary glue code to let DRM bridge drivers to implement CEC
adapters support.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20250517-drm-hdmi-connector-cec-v6-9-35651db6f19b@oss.qualcomm.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>