build_fu_desc
out_feature_unit_desc = build_fu_desc(audio_opts->c_chmask);
in_feature_unit_desc = build_fu_desc(audio_opts->p_chmask);
out_feature_unit_desc = build_fu_desc(uac2_opts->c_chmask);
in_feature_unit_desc = build_fu_desc(uac2_opts->p_chmask);