Comment 1 for bug 1907056

The kernel wants to use:
```
assets:
  pidtbs:
    update: true
    content:
      - dtbs/
```

instead of the one suggested above because the pi-kernel on arm64 and armhf have different dtbs/ dir layout:

arm64: dtbs/broadcom/*.dtb, dtbs/overlays
armhf: dtbs/*.dtb, dtbs/overlays

So the armhf has all the dtb files under dtbs/ directly and the arm64 has it under broadcom/.
 The suggestion is then that the gadget maps it from here to the right places.