iommufd: Allow an input data_type via iommu_hw_info

iommufd: Allow an input data_type via iommu_hw_info

The iommu_hw_info can output via the out_data_type field the vendor data
type from a driver, but this only allows driver to report one data type.

Now, with SMMUv3 having a Tegra241 CMDQV implementation, it has two sets
of types and data structs to report.

One way to support that is to use the same type field bidirectionally.

Reuse the same field by adding an "in_data_type", allowing user space to
request for a specific type and to get the corresponding data.

For backward compatibility, since the ioctl handler has never checked an
input value, add an IOMMU_HW_INFO_FLAG_INPUT_TYPE to switch between the
old output-only field and the new bidirectional field.

Link: https://patch.msgid.link/r/887378a7167e1786d9d13cde0c36263ed61823d7.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>