cfg80211: consider security during scan results update

AP security changes are not updated in the following scenario:
STA performs a scheduled scan on DFS channel during connection
to open AP, as some devices (wl12xx) will send a probe req on
DFS channels once activity is detected, cfg80211 gets and saves
the scan result from a probe resp. STA disconnected and AP
security is changed to AES, STA performs a passive scan,
cfg80211 gets a new scan result for the same BSSID but now from
beacon. cfg80211_bss_update() finds previous scan result from
probe resp but the security change is not updated correctly.
Fix this by considering security mismatch in rb_find_bss.

Signed-off-by: Victor Goldenshtein <victorg@ti.com>
wl12xx:support ap a2dp coex

Add functionality to support AP A2DP co-existence:

1. Add configuration for enable/disable of CTS protection in AP mode
2. Add indication for completion of connection establishment in ap
   mode. This is used by the firmware to change coex parameters
   when a station is in the process and connecting to the ap and
   change them back after the connection has been established.

Signed-off-by: Eyal Reizer <eyalr@ti.com>
wl12xx: fix unsafe dereference of the wlvif

wlvif could be passed as NULL from the wl1271_tx_work_locked()
to the wl1271_prepare_tx_frame() and to wl1271_skb_queue_head()
functions. This may lead to a Kernel panic, fix this by
validating that wlvif != NULL before using it.

Signed-off-by: Victor Goldenshtein <victorg@ti.com>