wifi: rtw89: correct 6 GHz scan behavior

Change active scan behavior to fit 6GHz requirements. There are many
different rules on active scan between 6GHz and 2GHz/5GHz, so if the
SSID is not specified, do fast passive scanning and limit number of
probe requests we send for now until new firmware can support all
rules.

Signed-off-by: Po-Hao Huang <phhuang@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/20221007045900.10823-1-pkshih@realtek.com