rt2x00: Log RT/RF chipset information correctly.

Some drivers (rt2800* most notably) cannot set the RF and RT chipset in
the correct order to have the information logging in rt2x00_set_chip
be correct.
Fix this by decoupling the setting of the chipset information from the
logging of the chipset information so that drivers can determine
themselves when all information is set.

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>