I'm monkeying around with an 881-W. Clients can associate and authenticate to ssid 'test', but they cannot get a DHCP address. Clients plugged into f 0 - 3 get DHCP addresses just fine.
I've looked at a lot of different guides, ran debugs etc. When wifi clients make DHCP requests the server never gets them. So there must be some IRB thing going on. Been banging my head on this wall for about an hour and figured it was time for an assist.
I've never played with an 881W before, but it looks to be like GigabitEthernet0 on the internal AP should be a trunked interface, not a routed link. The Gig0 interface on the router is a trunked link with VLAN 10 set to native. Try using the same configuration on the AP side. As for the IP address, move that over to the BVI1 interface.
no ip address
no bridge-group 1
encapsulation dot1q 10 native
ip add 192.168.1.2 255.255.255.0