infiniband: convert c2 to net_device_ops

Convert this driver to new net_device_ops infrastructure.
Also use default net_device get-stats infrastructure

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>