rt2x00/rt3352: Fix lnagain assignment to use register 66.

This should be register 66 instead of 62.
(probably happened by copy&past'ing from the lines below)

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