iommu/vt-d: Remove sva from intel_svm_dev

iommu/vt-d: Remove sva from intel_svm_dev

After commit be51b1d6bbff ("iommu/sva: Refactoring
iommu_sva_bind/unbind_device()"), the iommu driver doesn't need to
return an iommu_sva pointer anymore. This removes the sva field
from intel_svm_dev and cleanups the code accordingly.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20230109014955.147068-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>