virtio: remove unused virtio_find_vqs() and virtio_find_vqs_ctx() helpers

All callers of virtio_find_vqs() and virtio_find_vqs_ctx() were
converted to use virtio_find_vqs_info(). Remove no longer used helpers.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Message-Id: <20240708074814.1739223-19-jiri@resnulli.us>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>