wlcore: set channels 12-14 as pactive for sched scan

Introduce “pactive” scan mode – which instructs the fw to
perform a passive scan until an activity/energy is detected
on these channels, once energy detected the channel becomes
active.

Signed-off-by: Victor Goldenshtein <victorg@ti.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>