- move cxgb_tx_common in to cxgb_multiq.c and rename to cxgb_tx
- move cxgb_tx_common dependencies
- further simplify cxgb_dequeue_packet for the non-multiqueue case
- only launch one service thread per port in the non-multiq case
- remove dead cleaning code from cxgb_sge.c
- simplify PIO case substantially in by returning directly from mbuf collapse
and just using m_copydata
- remove gratuitous m_gethdr in the rx path
- clarify freeing of mbufs in collapse