mac80211: fix rate control update on 2040 bss change

The rate control updation never be called on 2040 BSS change.
The station should update its rate control on receiving beacon
with different HT mode in the HT operation IE. Not doing so,
leads to sending frames with higher(ht40) rates whereas AP is
operating in lower mode (ht20).

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>