hw.cxgbe.rsrv_noflow. When set, queue 0 of the port is reserved for
TX packets without a flowid. The hash value of packets with a flowid
is bumped up by 1. The intent is to provide a private queue for
link-level packets like LACP that is unlikely to overflow or suffer
deep queue latency.
Reviewed by: np
Obtained from: Netflix
MFC after: 3 days