net: axienet: Remove unused parameter from __axienet_device_reset

The dev parameter passed to __axienet_device_reset() is not used inside
the function, so remove it.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>