iommu/vt-d: Drop IOVA cookie management

The core code bakes its own cookies now.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/e9dbe3b6108f8538e17e0c5f59f8feeb714f51a4.1628682048.git.robin.murphy@arm.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>