You can change the regulatory domain (which channels) via:

/sys/devices/platform/wlan-omap/default_country.

The default it 0x10 and it is FCC but I don't think it says "FCC" (unsigned char [1], char [3]).

Setting the first byte to 0x01 appears to enable through at least channel 13 (2472)

I don't think the driver implements region 0x41 (MTK? japan) to allow 14/2482, but it might be something which can be edited in the source.

These won't show up on the settings dialog (there is a OSSO_PRODUCT_WLAN_CHANNEL variable that says FCC/US), but iwconfig and iwlist should be able to use the extra channels, and you might be able to edit something in /var/lib/gconf/system/osso/connectivity