mac80211: Fix station bandwidth setting after channel switch

[ Upstream commit 0007e94355fdb71a1cf5dba0754155cba08f0666 ]

When performing a channel switch flow for a managed interface, the
flow did not update the bandwidth of the AP station and the rate
scale algorithm. In case of a channel width downgrade, this would
result with the rate scale algorithm using a bandwidth that does not
match the interface channel configuration.

Fix this by updating the AP station bandwidth and rate scaling algorithm
before the actual channel change in case of a bandwidth downgrade, or
after the actual channel change in case of a bandwidth upgrade.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>