drivers/net: share vdev data to secondary process

drivers/net: share vdev data to secondary process

dpdk-procinfo, as a secondary process, cannot fetch stats for vdev.

This patch enables that by attaching the port from the shared data.
We also fill the eth dev ops, with only some ops works in secondary
process, for example, stats_get().

Note that, we still cannot Rx/Tx packets on the ports which do not
support multi-process.

Reported-by: Signed-off-by: Vipin Varghese <vipin.varghese@intel.com>
Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Reviewed-by: Qi Zhang <qi.z.zhang@intel.com>