platform/surface: aggregator_registry: Update comments for 15" AMD Surface Laptop 4

The 15" AMD version of the Surface Laptop 4 shares its WSID HID with the
15" AMD version of the Surface Laptop 3. Update the comments
accordingly.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20210523134528.798887-2-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>