agp/intel: add ValleyView AGP driver

... and bind it right to the PCI id.

Note that there are still a few things to fix here:
- we need to move the tlb flush to a better place in drm/i915.
- we need to check snoop support on vlv and implement it.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: squash follow-on patch and add todo items to commit msg.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/char/agp/intel-agp.c

@@ -907,6 +907,7 @@ static struct pci_device_id agp_intel_pci_table[] = {
 	ID(PCI_DEVICE_ID_INTEL_IVYBRIDGE_HB),
 	ID(PCI_DEVICE_ID_INTEL_IVYBRIDGE_M_HB),
 	ID(PCI_DEVICE_ID_INTEL_IVYBRIDGE_S_HB),
+	ID(PCI_DEVICE_ID_INTEL_VALLEYVIEW_HB),
 	{ }
 };