DACA patch against current benh tree

I've worked up a patch against BenH's current kernnel tree that (really,
this time) fixes DACA in three different ways:

  - Adds volume control for the DACA audio device,

  - Sets the necessary registers via I2C at sleep and wake times, so that
DACA audio will continue to work properly even after a sleep/wake cycle
(this will probably NOT work if the system is put to sleep before the
dmasound_pmac driver has been loaded, so it must be loaded at boot time),

  - Identifies rev. 2 and later KeyLargo as unable to do byteswap in
hardware, and when a little-endian format is passed when the
hw_can_byteswap flag is 0, changes the format to a big-endian one (for
apps like XMMS that check the return of the SETFMT ioctl).

Please check and make sure that this patch works (I'm using the driver
module built from it right now, so it _should_ work, but third-party
verification is probably a good idea anyway). If it does, please let Ben
Herrenschmidt know, so that he will know it's good for inclusion. (I will
CC: him with this mail.)

This does require the i2c-keywest driver to be loaded and available (all
Apple hardware uses pretty much the same I2C interface, and the KeyLargo
and UniNorth I2C devices are recognized by the i2c-keywest driver).

Derrik Pates      |   Sysadmin, Douglas School   |    #linuxOS on EFnet
dpates@dsdk12.net |     District (dsdk12.net)    |    #linuxOS on OPN