vfio/common: Add helper to validate iova/end against hostwin

vfio/common: Add helper to validate iova/end against hostwin

Move the code that finds the container host DMA window against a iova
range. This avoids duplication on the common checks across listener
callbacks.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Avihai Horon <avihaih@nvidia.com>
Link: https://lore.kernel.org/r/20230307125450.62409-6-joao.m.martins@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>