ixgbe: fix static functions

Define functions as static added C=1 (sparse) to my make line
brought these to my attention.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ixgbe/ixgbe_82599.c b/drivers/net/ixgbe/ixgbe_82599.c
index d521baf..d1cda36 100644
--- a/drivers/net/ixgbe/ixgbe_82599.c
+++ b/drivers/net/ixgbe/ixgbe_82599.c
@@ -494,7 +494,7 @@
  *
  *  Set the link speed in the AUTOC register and restarts link.
  **/
-s32 ixgbe_setup_mac_link_multispeed_fiber(struct ixgbe_hw *hw,
+static s32 ixgbe_setup_mac_link_multispeed_fiber(struct ixgbe_hw *hw,
                                           ixgbe_link_speed speed,
                                           bool autoneg,
                                           bool autoneg_wait_to_complete)