iommu/vt-d: Fix misuse of iommu_domain_identity_map()

iommu/vt-d: Fix misuse of iommu_domain_identity_map()

The iommu_domain_identity_map() helper takes start/end PFN as arguments.
Fix a misuse case where the start and end addresses are passed.

Fixes: c6068a7d5fe4a ("iommu/vt-d: Remove IOVA handling code from the non-dma_ops path")
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Tom Murphy <murphyt7@tcd.ie>
Link: https://lore.kernel.org/r/20200622231345.29722-7-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>