Remove 8SVX_RAW on next lavc mayor bump

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavcodec/avcodec.h

@@ -435,7 +435,9 @@ enum AVCodecID {
     AV_CODEC_ID_COMFORT_NOISE,
     AV_CODEC_ID_TAK_DEPRECATED,
     AV_CODEC_ID_FFWAVESYNTH = MKBETAG('F','F','W','S'),
+#if LIBAVCODEC_VERSION_MAJOR <= 54
     AV_CODEC_ID_8SVX_RAW    = MKBETAG('8','S','V','X'),
+#endif
     AV_CODEC_ID_SONIC       = MKBETAG('S','O','N','C'),
     AV_CODEC_ID_SONIC_LS    = MKBETAG('S','O','N','L'),
     AV_CODEC_ID_PAF_AUDIO   = MKBETAG('P','A','F','A'),