agp chipsets to drm_agpsupport.h, redid the card detection common code
to use a structure (avoids endian porting issues), changed the tdfx
driver to use the kernel pci id '#defines'
dev->agp, when agp_acquire called, and..... Uncomment MUST_HAVE_AGP
around agp_* calls, so that support for both agp/pci can happen in a
single kernel driver.