e1000e: correct ICH/PCH PHY operations function pointers

Some function pointers for a few PHY operations (for 82578 and 82567) and
were set incorrectly causing functions to be executed that were accessing
incorrect PHY register offsets for that particular device.  This patch also
moves a few PHY-specific functions from ich8lan.c to the more appropriate
phy.c.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>