pci_id_driver_map: Support preferring iris over i965

This adds the ability for intel devices that:

 * Only load on i965
 * Only load on iris
 * First attempt i965, and try iris next
 * First attempt iris, and try i965 next

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2 files changed