Oops when AGP support is missing

When installing the mga drm module, the kernel will oops if AGP support is present, but the system's AGP bridge is not supported. For example, if your kernel supports the Irongate, and your system contains a 440BX, the kernel will oops upon 'modprobe mga'. Additionally, the module cannot then be removed, since it will be jammed in the 'intialising' state.

This was reproduced on Linux 2.2.18pre24 with X 4.0.1h pulled on December 7. The system contains a VIA chipset, but the kernel was configured for Irongate.

-jwbaker@acm.org