TSF time might have been updated by the incoming beacon,
need update the channel switch timer to reflect the change.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>