rt2x00: Initialize rf302x RF values properly for rt2800pci.

Ensure RF302x and RF2020 chipsets are handled properly in rt2800lib
for the rt3090 chipset.

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>