The driver is written in such a way that with a board defintion that
connects a fixed phy, mdio, and switch in a certain way, a kernel oops could
result because of lack of previously probed mdio bus.
This commit allows for easier debugging in this case by casting the
correct blame with serial console messages.
Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>
7a3e133751