fix warning
/home/gitlab-runner/builds/tCBFNnUz/0/rep/ivas-codec-pc/ivas-codec/lib_rend/lib_rend.c:444:5: warning: enumeration value ‘IVAS_REND_AUDIO_CONFIG_LS_CUSTOM’ not handled in switch [-Wswitch]
/home/gitlab-runner/builds/tCBFNnUz/0/rep/ivas-codec-pc/ivas-codec/lib_rend/lib_rend.c:444:5: warning: enumeration value ‘IVAS_REND_AUDIO_CONFIG_LS_CUSTOM’ not handled in switch [-Wswitch]