amd-xgbe: Fix unused suspend handlers build warning

Fix:

  drivers/net/ethernet/amd/xgbe/xgbe-main.c:835:12: warning: ‘xgbe_suspend’ defined
    but not used [-Wunused-function]
  drivers/net/ethernet/amd/xgbe/xgbe-main.c:855:12: warning: ‘xgbe_resume’ defined
    but not used [-Wunused-function]

I see it during randconfig builds here.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>