Automatically recover from spurious PHY resets

[Gerharddc]

It seems my STM32-based board has a problem with spurious Ethernet PHY resets. This causes the connection to be dropped and it never manages to re-establish until I completely reset the board. I believe this is a hardware problem related to noise on the reset signal for the PHY and the goal is to fix it ASAP. However, in principle, this is an issue that the software should be able to recover from. It would thus be great if Embassy could automatically detect and recover from such a situation.

I have managed to get automated detection working in #3821 however, simply reconfiguring the PHY does not seem to fix the problem. My assumption is that something upstream in the stack also needs to be reset to deal with the PHY having been reset. Any ideas where to look?