snd_device_register — register the device
| int snd_device_register ( | struct snd_card * card, | 
| void * device_data ); | 
   Registers the device which was already created via
   snd_device_new.  Usually this is called from snd_card_register,
   but it can be called later if any new devices are created after
   invocation of snd_card_register.