drm/i915: Enable Haswell support

drm/i915: Enable Haswell support

* The drm/i915 driver includes its own set of PCI ids, making those in
  drm_pciids.h redundant. Remove i915/i930 ids from this file.

* Unfortunately our old drm code base expects to directly use device
  lists with a different format.

* Rewrite the i915_probe() routine to use the driver-included device
  list and patch a special-purpose, one-element list in the legacy
  format at runtime to make the old drm_attach() routine and associated
  code happy.

* At this point, Haswell GPUs still exhibit display corruption issues
  with 2D acceleration. Disabling it in xorg.conf is recommended.