iommu/vt-d: Add IOMMU_HWPT_ALLOC_PASID support

iommu/vt-d: Add IOMMU_HWPT_ALLOC_PASID support

Intel iommu driver just treats it as a nop since Intel VT-d does not have
special requirement on domains attached to either the PASID or RID of a
PASID-capable device.

Link: https://patch.msgid.link/r/20250321171940.7213-14-yi.l.liu@intel.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>