the addition of pci_find_extcap().
- Change the drm drivers to attach to vgapci. This is #ifdef'd so the
code can be shared across branches.
- Use pci_find_extcap() to look for AGP and PCIE capabilities in drm.
- GC all the drmsub stuff for i810/i830/i915. The agp and drm devices are
now both children of vgapci.