virtio-net: Mention that VIRTIO_NET_F_HASH_REPORT requires VIRTIO_NET_F_CTRL_VQ.

[Alvaro-Karsz]

If the VIRTIO_NET_F_HASH_REPORT feature is negotiated, the driver may
send VIRTIO_NET_CTRL_MQ_HASH_CONFIG commands, thus, the control VQ
is needed.

Since this was missed in 1.2, we can now add it as a "SHOULD".

https://lists.oasis-open.org/archives/virtio-comment/202302/msg00031.html

[mstsirkin]

unfortunately in 1.2 we already did not make this a dependency.
so we can make it a SHOULD since it makes sense, but not a MUST
without a feature bit.

[Alvaro-Karsz]

Ok, I'll fix the github issue and the patch.

[mstsirkin]

BALLOT CREATED AT URL: https://www.oasis-open.org/committees/ballot.php?id=3755