Catch FreeBSD up to the pcie gart changes. Required minor modification to

    radeon_cp.c to use a drm_local_map_t-type mapping (drm_core_ioremap
    rather than drm_ioremap), which contains private device mapping
    information on BSD. I also changed the ati_pcigart interface to use
    "void *" for pointers to kva rather than "unsigned long". While PCIGART
    support appears to be broken on FreeBSD currently, I think this is not
    new, and BusType PCI remains working on my r100 in Linux.