おまけ

sys/arch/sandpoint/conf/KUROBOXにこんなん足しておいた。

@@ -12,4 +12,10 @@
 satmgr0 at eumb? unit 0			# satmgr at 0x4500
 
 no nhpow0
 no gpio*
+
+# USB audio
+uaudio* at uhub? port ? configuration ?
+
+# Audio support
+audio*	at audiobus?

結果。

uaudio0: ONKYO Corporation USB Digital Audio Processor, rev 1.00/1.00, addr 2
uaudio0: ignored setting with precision 20
uaudio0: ignored setting with precision 20
uaudio0: ignored setting with precision 20
uaudio0: ignored setting with precision 20
uaudio0: audio rev 1.00
audio0 at uaudio0: full duplex, playback, capture, independent

なんかignoreゆーとるがとりあえず認識できたっぽい。