all: remove unused functions from includes

Signed-off-by: Mahyar Koshkouei <mk@deltabeard.com>

include/vorbis.h

@@ -3,19 +3,4 @@
 #include "playback.h"
 
 void setVorbis(struct decoder_fn* decoder);
-
-int initVorbis(const char* file);
-
-uint32_t rateVorbis(void);
-
-uint8_t channelVorbis(void);
-
-uint64_t decodeVorbis(void* buffer);
-
-void exitVorbis(void);
-
-int playVorbis(const char* in);
-
-uint64_t fillVorbisBuffer(char* bufferOut);
-
 int isVorbis(const char* in);