ath11k: Add support for 6g scan hint

Add support for 6Ghz short ssid and bssid hint mechanism
as part of scan command.

Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200603001724.12161-9-pradeepc@codeaurora.org