ixgbe: Add X553 PHY FC autoneg support

ixgbe: Add X553 PHY FC autoneg support

Orabug: 24568240

This patch adds X553 flow control auto negotiation for fiber and
backplain.  To enable this new function pointers were added as well
as creating a function to dynamically set function pointer we can't
define only on MAC type.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 2916500db3075cf2dd7968fe0f140ef4df7c6d31)
Signed-off-by: Brian Maly <brian.maly@oracle.com>