ixgbe: Power down PHY during driver resets

The PHY laser is still on during driver init.  It's allowing
garbage to hit our FIFO, which eventually can cause the entire
device to die.  Power down the laser while setting up the device,
and re-enable the laser before getting link.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>