rtw89: coex: Define LPS state for BTC using

To distinguish three types of LPS state.

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/20211209083229.10815-5-pkshih@realtek.com