drm_select_eld requires mode_config.mutex and connection_mutex
because it looks at the connector list and at the legacy encoders.

This is not required, because when we call audio_codec_enable we know
which connector it was called for, so pass the state.

This also removes having to look at crtc->config.

Changes since v1:
- Use intel_crtc->pipe instead of drm_crtc_index. (Ville)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1478609742-13603-8-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>