wifi: rtw89: 8852c: set TX to single path TX on path B in 6GHz band

With one path TX for 1SS rate, it can transmit higher power in 6GHz band
to yield better performance in high attenuation circumstance.

Signed-off-by: Yi-Tang Chiu <chiuyitang@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/20220908051257.25353-5-pkshih@realtek.com