igb: add support for 82576NS SerDes adapter

This patch adds the device ID necessary to support the 82576NS SerDes
adapter.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/igb/e1000_hw.h b/drivers/net/igb/e1000_hw.h
index 7b7898b..4e7850d 100644
--- a/drivers/net/igb/e1000_hw.h
+++ b/drivers/net/igb/e1000_hw.h
@@ -42,6 +42,7 @@
 #define E1000_DEV_ID_82576_SERDES             0x10E7
 #define E1000_DEV_ID_82576_QUAD_COPPER        0x10E8
 #define E1000_DEV_ID_82576_NS                 0x150A
+#define E1000_DEV_ID_82576_NS_SERDES          0x1518
 #define E1000_DEV_ID_82576_SERDES_QUAD        0x150D
 #define E1000_DEV_ID_82575EB_COPPER           0x10A7
 #define E1000_DEV_ID_82575EB_FIBER_SERDES     0x10A9