drm/i915: Fix audio ELD handling for DP MST

I forgot to call intel_audio_compute_config() on DP MST, which
means ELD doesn't get populated and passed to the audio driver.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/8097


Fixes: 5d986635 ("drm/i915/audio: Precompute the ELD")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230220151731.6852-1-ville.syrjala@linux.intel.com


Reviewed-by: Uma Shankar <uma.shankar@intel.com>
(cherry picked from commit 518b761a)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>