wl12xx: use split scan for normal scan

Split scan allows the FW to schedule other activities
during a scan which may be a long operation. This is
achieved by setting a trigger TID to ANY_TID and a scan
trigger timeout other than 0. The default one is set to 50ms.

Signed-off-by: Eyal Shapira <eyal@wizey.com>
Signed-off-by: Igal Chernobelsky <igalc@ti.com>
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>