e1000e: cosmetic move of #defines and prototypes to the new ich8lan.h

Move #defines and function prototypes specific to the ICH/PCH family of
devices (ICH8/82562, ICH8/82566, ICH8/82567, ICH9/82562, ICH9/82566,
ICH9/82567, ICH10/82567, 82577, 82578, 82579, I217, I218) to the new
ich8lan.h header file (the convention for Intel wired ethernet drivers is
to use the name of the first device in the family for related file and
function names).  These defines and function prototypes can be used by
other files in the driver and moving them to the ICH/PCH-family-specific
file makes it clearer to which devices they are applicable.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>