Secondary unicast and multicast addresses are added to the Receive
Address registers (RAR) for most parts supported by the driver.  For
82579, there is only one actual RAR and a number of Shared Receive Address
registers (SHRAR) that are shared among the driver and f/w which can be
reserved and write-protected by the f/w.  On this device, use the SHRARs
that are not taken by f/w for the additional addresses.

Add a MAC ops function pointer infrastructure (similar to other MAC
operations in the driver) for setting RARs, introduce a new rar_set
function for 82579 and convert the existing code that sets RARs on other
devices to a generic rar_set function.
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>