rtlwifi: btcoex: add assoc type v2 to connection notify

In connection notify v1, btcoex only need to know start/end association,
and it will discriminate 2G and 5G band in v2.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>