drm/i915: Wrap g4x+ DP/HDMI audio enable/disable

Put a wrapper around the intel_audio_codec_{enable,disable}()
calls in the g4x+ DP/HDMI code. We shall move the presence
detect enable/disable into the wrappers later.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231121054324.9988-6-ville.syrjala@linux.intel.com