So, the same name + depth ?

 +---|-PHY+
 |   |    |
 | SerDes |
 |   |    |
 |  PCS   | component = PHY, name = "pcs", depth = 0
 |   |    |
 |  MAC   |
 |   |    |
 | packet |
 | buffer |
 |   |    |
 |  MAC   |
 |   |    |
 |  PCS   | component = PHY, name = "pcs", depth = 1
 |   |    |
 |  PMA   |
 |   |    |
 |  PMD   |
 +---|----+
     |
     v 10GBaseT

For that we have what we need with phy_link_topology, as each PHY has
its index, we should be good to go in that regard hopefully :)

So depth would be local to a component? We could have two PHY
components, each with a different index, and depth = 0?

I _think_ Jakub's depth was more at a global level? But then it would
need to be passed down as we do the enumeration.

     Andrew