iommu/vt-d: Update register definitions to VT-d 3.0 specification

Add new register definitions added in the VT-d 3.0 specification. Also
include registers that were missing previously.

Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Gayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>