wcn36xx: disable HW_CONNECTION_MONITOR

Whenever the signal stregth decays smoothly and physical connnection
is already gone and no deauth has arrived, the qcom soc is not
able to indicate neither WCN36XX_HAL_MISSED_BEACON_IND nor
WCN36XX_HAL_MISSED_BEACON_IND. It was noticed that such situation gets
even more reproducible, when the driver fails to enter bmps mode - which is
highly likely to occur. Thus, in order to provide proper disconnection
of the connected STA, let mac80211 handle it, instead of wcn3xx driver.

Signed-off-by: Eduardo Abinader <eduardoabinader@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>