Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC of R267935: Sync the E1000 shared code to Intel internal, and
more importantly add new I218 adapter support to em.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Update the Intel igb driver to version 2.4.0
- This version has support for the new Intel Avoton systems,
including 2.5Gb support, further it now has IPv6/TSO6 support as
well. Shared code has been updated where necessary as well. Thanks
to my new assistant Eric Joyner for doing the transmit path changes
to bring in the IPv6/TSO6 support. Thanks to Gleb for catching the
one bug and change needed in NETMAP.

Approved by: re

Refresh on the shared code for the E1000 drivers.
- bear with me, there are lots of white space changes, I would not
do them, but I am a mere consumer of this stuff and if these drivers
are to stay in shape they need to be taken.

em driver changes: support for the new i217/i218 interfaces

igb driver changes:
- TX mq start has a quick turnaround to the stack
- Link/media handling improvement
- When link status changes happen the current flow control state
will now be displayed.
- A few white space/style changes.

lem driver changes:
- the shared code uncovered a bogus write to the RLPML register
(which does not exist in this hardware) in the vlan code,this
is removed.

Sync with Intel internal source:
shared code update and small changes in core required
Add support for new i210/i211 devices
Improve queue calculation based on mac type

MFC after:5 days