wifi: rtw89: recognize log format from firmware file

Firmware log format is an element of multi-firmware file
and used for firmware to provide log with formatted text.
Driver needs to recognize it in advance if it exists.

Signed-off-by: Chin-Yen Lee <timlee@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/20230801021127.15919-2-pkshih@realtek.com