ixgbe: add support for active DA cables

This patch adds support of active DA cables.  This is
renaming and adding some PHY type enumerations.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>