MFC r221445:

MFC r221445:
  Add initial BCM57765 family support. The BCM57765 family seems to
  have similar hardware features of BCM5718 family except the number
  of receive return ring is 4. The BCM57765 family is known to
  support IEEE 802.3az EEE(Energy Efficient Ethernet) but this change
  does not include EEE support code. I hope EEE is implemented in
  near future.
  This change will support BCM57761, BCM57765, BCM57781, BCM57785,
  BCM57791 and BCM57795. All hardware offloading features are
  supported and suspend/resume also should work.
  Many thanks to Broadcom for continuing support of FreeBSD.

  Tested by:	Paul Thornton (prt <> prt dot org)
  HW donated by:	Broadcom

git-svn-id: svn://svn.freebsd.org/base/stable/8@222144 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f