iommu/s390: set appropriate IOTA region type

When registering the I/O Translation Anchor, use the current table type
stored in the s390_domain to set the appropriate region type
indication.  For the moment, the table type will always be stored as
region third.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20250411202433.181683-2-mjrosato@linux.ibm.com


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