MFC r295323:

MFC r295323:
Update em(4) to 7.6.1; update igb(4) to 2.5.3.

Major changes:

- Add i219/i219(2) hardware support. (Found on Skylake generation and newer
  chipsets.)
- Further to the last Skylake support diff, this one also includes support for
  the Lewisburg chipset (i219(3)).

- Add a workaround to an igb hardware errata.
  All 1G server products need to have IPv6 extension header parsing turned off.
  This should be listed in the specification updates for current 1G server
  products, e.g. for i350 it's errata #37 in this document:
  http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/ethernet-controller-i350-spec-update.pdf

- Avoton (i354) PHY errata workaround added

And a bunch of minor fixes, as well as #defines for things that the current
em(4)/igb(4) drivers don't implement.

MFC r287465:

igb(4): Update and fix HW errata
- HW errata workaround for IPv6 offload w/ extension headers
- Edited start of if_igb.c (Device IDs / #includes) to match ixgbe/ixl

Approved by: re (gjb)
Sponsored by: Intel Corporation

git-svn-id: svn://svn.freebsd.org/base/stable/10@296055 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f