will merge isaki-audio2 branch

[Tetsuya Isaki <isaki%pastel-flower.jp@localhost>]

Hello all,

I will merge isaki-audio2 branch into -current in a few days
(if there is no problem).
The main purpose of this branch is not completion of all audio
drivers.  The reason I've branched is that there were some
unbuildable period during importing.

Here is the drivers that I've confirmed or I've received report
that it works (at least one model on one port):
 arcofi(4) audiocs(4) auich(4) autri(4) bba(4) cmpci(4) dbri(4)
 eap(4)[*] emuxki(4) ess(4) haltwo(4) hdafg(4) mavb(4) pad(4)
 sb(4)[*] snapper(4) uaudio(4) vs(4) vsaudio(4) wss(4)
 aica(4) (not commited yet but thanks ryo@-san)
 yds(4) (not commited yet, I will commit it later)

 Note:
  eap(4): works on VMware.  But I heard that a real ES1373 card
   on alpha/macppc outputs bunch of "eap1371_ready_codec timeout [23]"
   (even on netbsd-8).  Can someone confirm this? (I think hardware
   failure.)

  sb(4): works on VirtualBox (SB16).  But I heard that a real SBPro
   (SoundBlaster compatible mode on ES1887) doesn't work (even on
   netbsd-8).  It looks that no interrupts occur.  Can someone take
   this?

The other drivers not listed here may or may not work.  But it
should work if it have worked before.  Please test your sound card
regardless of before or after merging.

Thanks,
---
Tetsuya Isaki <isaki%pastel-flower.jp@localhost / isaki%NetBSD.org@localhost>