vfio/type1: introduce a new member has_rsvd for struct vfio_dma

Introduce a new member has_rsvd for struct vfio_dma. This member is
used to indicate whether there are any reserved or invalid pfns in
the region represented by this vfio_dma. If it is true, it indicates
that there is at least one pfn in this region that is either reserved
or invalid.

Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20250814064714.56485-5-lizhe.67@bytedance.com


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