wil6210: Support hidden SSID

Pass hidden SSID information to FW for proper operation.
In order to be able to scan/connect to the hidden SSID, SSID
setting is added when scan is requested from FW. SSID
scanning currently supports single SSID due to FW limitation.

Signed-off-by: Hamad Kadmany <qca_hkadmany@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>