[TF-M] AN521 debugging

As the IAR ports for Musca A and psoc64 are more or less complete, I've started looking at the MPS2/MPS3 targets.

After some initial issues I can now connect our debugger via USB using CMSIS-DAP. However I'm not getting and serial ports configured on my Win10 laptop when connecting to an MPS2+ board running the AN521 (M33) image. Shouldn't that show up automatically like it does with the MPS3? Or do I need to use the physical serial port on the board?

I would appreciate reviews of the IAR port as well, see https://review.trustedfirmware.org/c/trusted-firmware-m/+/3295

Thanks, Thomas