vfio/type1: Check reserved region conflict and update iova list

This retrieves the reserved regions associated with dev group and
checks for conflicts with any existing dma mappings. Also update
the iova list excluding the reserved regions.

Reserved regions with type IOMMU_RESV_DIRECT_RELAXABLE are
excluded from above checks as they are considered as directly
mapped regions which are known to be relaxable.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>