net/mlx5: E-switch, Handle multiple master egress rules

Currently, whenever a shared FDB is created, the slave eswitch is
creating master egress rule to the master eswitch.
In order to support more than two ports, which means there will be
more than one slave eswitch, enlarge bounce_rule, which is used to
create master egress rule, to an xarray.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>