iommu/vt-d: Implement hw_info for iommu capability query

Add intel_iommu_hw_info() to report cap_reg and ecap_reg information.

Link: https://lore.kernel.org/r/20230818101033.4100-6-yi.l.liu@intel.com


Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>