rtlwifi: btcoex: 21a 2ant: dec bt power according to bt rssi and set tdma

Check the bt rssi first and decrease it if the bt rssi is too high.
Then set the tdma and coex table.

Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Pkshih <pkshih@realtek.com>
Cc: Birming Chiu <birming@realtek.com>
Cc: Shaofu <shaofu@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>