Need to turn off  SGE RX/TX Callback Timers & interrupt in cxgb4vf PCI Shutdown
routine in order to prevent crashes during reboot/poweroff when traffic is
running.
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>