pcidevs: Add device ID for Sundance ST201
ste: Add another PCI device ID for Sundance ST201

DragonFly-bug: http://bugs.dragonflybsd.org/issues/2529
vr: Remove extra VR_ISR_RX_NOBUF test

Pointed-out-by: swildner@
tcp: Cache align tcp_stats

- tcp_stats is padded to multiple cache line size; add comment about it
- Cache align the per-cpu tcp_stats array