devlink: Add relation between dpipe and resource

The hardware processes which are modeled via dpipe commonly use some
internal hardware resources. Such relation can improve the understanding
of hardware limitations. The number of resource's unit consumed per
table's entry are also provided for each table.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>