Actually, any DHCP server that is created on the controller automatically sends out DHCP option 60 and 43 for the management ip address of the controller in the background.
If you know the ip address that the AP gets, get on the controller and type "show datapath session table <ip address of ap>" repeatedly when the AP is booting up to see if any of the traffic on the AP even makes it to the controller. The other option is to connect to the access point's console port to see what ip address the AP gets and what it is attempting to do, and where things fail.