e1000e: split lib.c into three more-appropriate files

The generic lib.c file contains code relative to the various MACs, NVM and
Manageability supported by the driver.  This patch splits the file into
three which are specific to those areas similar to how the PHY-specific
code is in phy.c and code specific to the 80003es2lan, 8257x, and ichX
MAC families are in their own files.  The generic code that is applicable
to all MAC/PHY parts supported by the driver remains in netdev.c, param.c
and ethtool.c files.  No change in functionality, just moving code
around for ease of maintenance, with some whitespace and other checkpatch
cleanups.

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>