iommu/vt-d: Support IOMMU_DEV_FEAT_IOPF

Allow drivers to query and enable IOMMU_DEV_FEAT_IOPF, which amounts to
checking whether PRI is enabled.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210401154718.307519-5-jean-philippe@linaro.org


Signed-off-by: Joerg Roedel <jroedel@suse.de>