[U-Boot] e1000: Driver additions for eXMeritus HWW-1U-1A

[Kyle Moffett]

Sorry for taking so long to update and re-post these; I've had a lot of other
things on my plate for the last several months.  I've re-based them against
the latest U-Boot master branch as of today.

The following 5 patches are a series to provide the necessary support for
the onboard Intel 82571 E1000E chips on our eXMeritus HWW-1U-1A boards.

There are a few incidental fixups for dual-port NICs, but the main body of
these patches is an SPI driver and "e1000 eeprom" commands for programming
the configuration EEPROM attached to the 82571 chips.

Our manufacturing process directly attaches the unprogrammed EEPROMs to the
boards.  We then use this code to load the Intel EEPROM and update the
MAC address.

The overall diffstat is:
 drivers/net/e1000.c |  848 ++++++++++++++++++++++++++++++++++++++++++++-------
 drivers/net/e1000.h |   18 +-
 2 files changed, 751 insertions(+), 115 deletions(-)

Most of the new code is hidden behind a couple of config options, so it won't
affect other users of e1000 chips unless they explicitly request it.

Cheers,
Kyle Moffett