net/mlx5: Bridge, add tracepoints for multicast

Pass target struct net_device to mdb attach/detach handler in order to
expose the port name to the new tracepoints. Implemented following
tracepoints:

- Attach mdb to port.
- Detach mdb from port.

Usage example:

># cd /sys/kernel/debug/tracing
># echo mlx5:mlx5_esw_bridge_port_mdb_attach >> set_event
># cat trace
...
     kworker/0:0-19071   [000] ..... 259004.253848: mlx5_esw_bridge_port_mdb_attach: net_device=enp8s0f0_0 addr=33:33:ff:00:00:01 vid=0 num_ports=1 offloaded=1

Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>