The overrun ignore bit isn't supported by the device's firmware and was
recently removed from the programmer's reference manual (PRM).

Remove it from the driver as well.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>