wil6210: correctly report locally generated disconnect in STA mode

Driver always invoke cfg80211_disconnected() with locally_generated as
false.
Fix this by reporting true whenever the disconnect is triggered from
upper layers (cfg80211) or from within the driver itself (reset,
deinit).

Signed-off-by: Dedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>