Bug#323724: found the culprit

[Paul Brossier <piem@altern.org>]

the culprit was CONFIG_FB_NVIDIA, which should not be set. the following
changes fix the boot on PowerMac 7,2, and add support for the soundcard.

cheers, paul

$ diff /boot/config-2.6.12-1-powerpc64 /boot/config-2.6.12-powerpc64def
3,4c3,4
< # Linux kernel version: 2.6.12-1-powerpc64
< # Tue Sep  6 23:15:30 2005
---
> # Linux kernel version: 2.6.12-powerpc64def
> # Sat Sep 17 18:52:33 2005
1542c1543
< CONFIG_FB_NVIDIA=y
---
> # CONFIG_FB_NVIDIA is not set
1686c1687
< # CONFIG_SND_POWERMAC is not set
---
> CONFIG_SND_POWERMAC=m