ALSA: rawmidi: remove undefined functions.

'snd_rawmidi_transmit_reset()' and 'snd_rawmidi_receive_reset()' are declared
but not defined.

This state has been continue over 10 years. So let us remove them.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/rawmidi.h

@@ -157,10 +157,8 @@ void snd_rawmidi_set_ops(struct snd_rawmidi *rmidi, int stream,
 
 /* callbacks */
 
-void snd_rawmidi_receive_reset(struct snd_rawmidi_substream *substream);
 int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
 			const unsigned char *buffer, int count);
-void snd_rawmidi_transmit_reset(struct snd_rawmidi_substream *substream);
 int snd_rawmidi_transmit_empty(struct snd_rawmidi_substream *substream);
 int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
 			      unsigned char *buffer, int count);