virtio: Accept VIRTIO_F_RING_RESET in the modern PCI transport

Accept per-virtqueue reset when the device offers it, alongside
the V1 flag. Negotiating the feature merely permits the use of
per-virtqueue reset and imposes no obligation on a driver that
never uses it, while refusing capability-only transport features
can make strict devices reject the feature set altogether.

No functional change on hosts that do not offer RING_RESET.

Signed-off-by: Faraz Vahedi <kfv@kfv.io>
Reviewed-by: ngie
Pull-Request: https://github.com/freebsd/freebsd-src/pull/2319