Wireless: Fix Kconfig fact error

Raytheon cards use 2.4 GHz, not 2.4 MHz.
See http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/Linux.Wireless.drivers.html#Raylink



Signed-off-by: Erik Ekman <erik@kryo.se>
Signed-off-by: John W. Linville <linville@tuxdriver.com>