vfio: Make vfio_devices_query_dirty_bitmap() static

vfio: Make vfio_devices_query_dirty_bitmap() static

vfio_devices_query_dirty_bitmap() is only used in "container-base.c".
Also, rename to vfio_container_devices_query_dirty_bitmap() to reflect
with the prefix 'vfio_container_devices_' that it simply loops over
the container's device list.

Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Avihai Horon <avihaih@nvidia.com>
Link: https://lore.kernel.org/qemu-devel/20250326075122.1299361-28-clg@redhat.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>