iommu/amd: Return devid as alias for ACPI HID devices

ACPI HID devices do not actually have an alias for
them in the IVRS. But dev_data->alias is still used
for indexing into the IOMMU device table for devices
being handled by the IOMMU. So for ACPI HID devices,
we simply return the corresponding devid as an alias,
as parsed from IVRS table.

Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Fixes: 2bf9a0a1

 ('iommu/amd: Add iommu support for ACPI HID devices')
Signed-off-by: Joerg Roedel <jroedel@suse.de>