ixgbe: Add SR-IOV specific features

This module and header file add functions to support SR-IOV features of the
82599 10Gbe controller.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>