It's not possible (from what I can see) to enable snmp on the lightweight/thin APs. At least not the AIR-LAP1142N or the AIR-CAP3602I that we are using.
It would be great if you would retrieve more info from the Controller about each AP, like CDP, Serial number, uptime etc
Also, based on the ip address, it should be possible for you to link the AP with the ICMP polled device.
I can see that I'm not the only one seeking this: