MFC r220649, r220874

MFC r220649, r220874

r220649:
Fix a couple of bad races that can occur when a cxgbe interface is taken
down.  The ingress queue lock was unused and has been removed as part of
these changes.

- An in-flight egress update from the SGE must be handled before the
  queue that requested it is destroyed.  Wait for the update to arrive.

- Interrupt handlers must stop processing rx events for a queue before
  the queue is destroyed.  Events that have not yet been processed
  should be ignored once the queue disappears.

r220874:
Use Toeplitz hash for RSS.

git-svn-id: svn://svn.freebsd.org/base/stable/8@220936 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f