No you can not do this on the AP. WLAN is a shared media just the same as you could not limit bandwidth per client on a hub you can not do this on the AP.
You do however have several options to do this further upstream
Most Cisco switches support QoS and you can use policing to control bandwidth utilisation and products like BBSM and SSG both have the option to limit bandwidth based on user profiles.
These methods will not stop the end device using the total bandwidth at any given time but rely on the built in flow control methods of tcp windowing etc This gives the net effect of bandwidth control
DO NOT TRY to do this using data rates as everyone shares these data rates