This patch add support for X552 XFI backplane interface.  The XFI
backplane requires a custom tuned link.  HW/FW owns the link config
for XF backplane and SW must not interfere with it.
Signed-off-by: NDon Skidmore <donald.c.skidmore@intel.com>
Tested-by: NKrishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>