ixgbe: fix broken PFC with X550

PFC is configuration is skipped for X550 devices due to a incorrect
device id check, fixing that to include X550 PFC configuration.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>