iommu/vt-d: Save the right domain ID used by hardware

The driver sets a default domain id (FLPT_DEFAULT_DID) in the
first level only pasid entry, but saves a different domain id
in @sdev->did. The value saved in @sdev->did will be used to
invalidate the translation caches. Hence, the driver might
result in invalidating the caches with a wrong domain id.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Fixes: 1c4f88b7 ("iommu/vt-d: Shared virtual address in scalable mode")
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>