ALSA: snd-usb: switch over to new endpoint streaming logic

With the previous commit that added the new streaming model, all
endpoint and streaming related code is now in endpoint.c, and pcm.c
only acts as a wrapper for handling the packet's payload.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/endpoint.h

@@ -15,9 +15,6 @@ void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force);
 int snd_usb_substream_prepare(struct snd_usb_substream *subs,
 			      struct snd_pcm_runtime *runtime);
 
-int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd);
-int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd);
-
 
 #define SND_USB_ENDPOINT_TYPE_DATA     0
 #define SND_USB_ENDPOINT_TYPE_SYNC     1