rtw88: coex: Add WLAN MIMO power saving for Bluetooth gaming controller

To keep high sensitivity reaction, Bluetooth gaming controller will send
packet very frequently, it will make WLAN performance very poor. To solve
this situation, MIMO PS mechanism makes WLAN/BT own an antenna itself, WLAN
quits 2SS performance but it can get a stable 1SS performance and Bluetooth
gaming controller can keep sensitivity reaction at the same time.

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://lore.kernel.org/r/20220215004855.4098-5-pkshih@realtek.com