e1000e: workaround EEPROM configuration change on 82579

An update to the EEPROM on 82579 will extend a delay in hardware to fix an
issue with WoL not working after a G3->S5 transition which is unrelated to
the driver.  However, this extended delay conflicts with nominal operation
of the device when it is initialized by the driver and after every reset
of the hardware (i.e. the driver starts configuring the device before the
hardware is done with it's own configuration work).  The workaround for
when the driver is in control of the device is to tell the hardware after
every reset the configuration delay should be the original shorter one.

Some pre-existing variables are renamed generically to be re-used with
new register accesses.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>