rt2x00: RF3052 is a valid RF chipset for USB devices as well.

The RF3052 chipset is now also being integrated onto USB devices, so
allow the RF chipset and don't treat it as PCI/SOC only.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>