wifi: rtw89: coex: To improve Wi-Fi performance while BT is idle

Because some platform Bluetooth will have many background scan when idle.
And the frequently Bluetooth scan will break Wi-Fi traffic many times at
a short duration, it will make Wi-Fi throughput become lower. This patch
will shorter Bluetooth slot and adjust priority settings, make Wi-Fi can
have a more completed duration to do traffic.

Signed-off-by: Ching-Te Ku <ku920601@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20231218061341.51255-12-pkshih@realtek.com