vfio/pds: Pass region info to relevant functions

A later patch in the series implements multi-region
support. That will require specific regions to be
passed to relevant functions. Prepare for that change
by passing the region structure to relevant functions.

Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-5-brett.creeley@amd.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>