pcm config files cleanups and name hint extension

- remove device 0/subdevice 0 from configuration files (it's default)
- name_hint
  - fixed parsing slaves
  - obtain device numbers directly from 'type hw' configurations to
    avoid poluting of configurations scripts with hint.device lines

src/conf/cards/VIA686A.conf

@@ -14,7 +14,6 @@ VIA686A.pcm.front.0 {
 	}
 	type hw
 	card $CARD
-	device 0
 }	
 
 # default with dmix/dsnoop
@@ -63,28 +62,24 @@ VIA686A.pcm.iec958.0 {
 	slave.pcm {
 		type hw
 		card $CARD
-		device 0
 	}
 	hooks.0 {
 		type ctl_elems
 		hook_args [
 			{
 				name "IEC958 Playback AC97-SPSA"
-				device 0
 				lock true
 				preserve true
 				value 0
 			}
 			{
 				name "IEC958 Playback Default"
-				device 0
 				lock true
 				preserve true
 				value [ $AES0 $AES1 $AES2 $AES3 ]
 			}
 			{
 				name "IEC958 Playback Switch"
-				device 0
 				lock true
 				preserve true
 				value true