wil6210: support new WMI-only FW capability

WMI_ONLY FW is used for testing in production. It cannot be used for
scan/connect, etc.
In case FW reports this capability, driver will not allow interface up.

Signed-off-by: Dedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>