Remove Sonic experimental audio codec

Since initially committed in 2004, this codec has only been touched
for maintenanance.  Functionally, it contains no novel ideas and
its intended audience is better served by existing mature codecs.

Signed-off-by: Mans Rullgard <mans@mansr.com>

libavcodec/allcodecs.c

@@ -266,8 +266,6 @@ void avcodec_register_all(void)
     REGISTER_DECODER (SHORTEN, shorten);
     REGISTER_DECODER (SIPR, sipr);
     REGISTER_DECODER (SMACKAUD, smackaud);
-    REGISTER_ENCDEC  (SONIC, sonic);
-    REGISTER_ENCODER (SONIC_LS, sonic_ls);
     REGISTER_DECODER (TRUEHD, truehd);
     REGISTER_DECODER (TRUESPEECH, truespeech);
     REGISTER_DECODER (TTA, tta);