wifi: rtw89: coex: Add coexistence policy for hardware scan

Add additional policy option to let Bluetooth audio can play well
during Wi-Fi is hardware scanning.

Signed-off-by: Ching-Te Ku <ku920601@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20240626023129.7776-1-pkshih@realtek.com