wifi: rtw89: config EDCCA threshold during scan to prevent TX failed

Need to configure EDCCA threshold to default value before scan, and recall
original value after scan to prevent probe request can't be sent out.

Signed-off-by: Chih-Kang Chang <gary.chang@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/20230322060238.43922-1-pkshih@realtek.com