CONFIG_NET_RADIO is obsolete as of kernel 2.6. (It is part of the OLD wireless network drivers before the new API was introduced.)
You could configure a 2.4 kernel that way . . . no need for that, though.
The prism2 is supported I believe. (The Atheros driver . . .?) Most distributions' kernels should support it by default. If you know the make and model of the card, you can locate it in the LQ HCL:
http://www.linuxquestions.org/hcl/index.php/cat/10