iommufd/fault: Move two fault functions out of the header

iommufd/fault: Move two fault functions out of the header

There is no need to keep them in the header. The vEVENTQ version of these
two functions will turn out to be a different implementation and will not
share with this fault version. Thus, move them out of the header.

Link: https://patch.msgid.link/r/7eebe32f3d354799f5e28128c693c3c284740b21.1741719725.git.nicolinc@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>