Add new programmer for SPI EEPROMs attached to Intel 82580 NICs.

This patch lets you read and write the EEPROM on 82580-based gigabit NIC
cards. So far it has been tested on copper NICs only, but other variants
employing this controller should work too.
It is a nice substitution for the official eeupdate tool.

Speed is quite decent: less than 4 seconds for erases or writes of 32 kB.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Tested-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1832 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1