iommufd/selftest: Add coverage for IOMMU_HWPT_INVALIDATE ioctl

Add test cases for the IOMMU_HWPT_INVALIDATE ioctl and verify it by using
the new IOMMU_TEST_OP_MD_CHECK_IOTLB.

Link: https://lore.kernel.org/r/20240111041015.47920-7-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>