Document r306660, Virtual Function devices on T4 and T5 adapters.
Document r306661, TCP Offload Engine on Chelsio T4+ adapters.
Document r306664, cxgbev(4) addition.
Document r309560, several cxgbe(4) and cxgbev(4) updates.

Submitted by: jhb
Sponsored by: The FreeBSD Foundation