Simplify display info update by merging ELD handling as well as clearing
of the data in update_display_info().

The connector->eld really should be moved under display_info altogether,
but that's for another time.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1f2e7424b998fbcdd9cea488e7d6d7cbb26c460f.1672826282.git.jani.nikula@intel.com