(split off from the earlier RT35xx patch submitted by Shiang)

There's no point in enabling the PA_PE bits for the bands that we are
not active on.
Signed-off-by: NShiang Tu <shiang_tu@ralinktech.com>
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>