drm/cec: add drm_dp_cec_attach() as the non-edid version of set edid

Connectors have source physical address available in display
info. There's no need to parse the EDID again for this. Add
drm_dp_cec_attach() to do this.

Seems like the set_edid/unset_edid naming is a bit specific now that
there's no need to pass the EDID at all, so aim for attach/detach going
forward.

v2: Fix the embarrashing build failures

Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: linux-media@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230825130120.1250089-1-jani.nikula@intel.com