brcmfmac: use control channel in roamed status reporting

Channel reported in scan results passed to cfg80211 is control
channel. But chanspec is reported while notifying cfg80211 about
roamed update. Cfg80211 complains because it could not find the
bss in the list. Report control channel while calling
cfg80211_roamed.

Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>