platform/surface: aggregator_registry: Change device ID for base hub

Use the target category of the (base) hub as instance id in the
(virtual) hub device UID. This makes association of the hub with the
respective subsystem easier.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220527023447.2460025-11-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>