iommu/vt-d: Enable ATS only if the device uses page aligned address.

As per Intel vt-d specification, Rev 3.0 (section 7.5.1.1, title "Page
Request Descriptor"), Intel IOMMU page request descriptor only uses
bits[63:12] of the page address. Hence Intel IOMMU driver would only
permit devices that advertise they would only send Page Aligned Requests
to participate in ATS service.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>