When doing active scan on crowded channels we are likely to miss probe
responses due to collisions. To overcome this issue we use an extended
dwell time on channels 1, 6 and 11; this dwell time is set to 100.

In case of fragmented scan extended dwell time is the maximum out of
channel time - 44 msec. Fragmented active scan will be addressed later.

Extended dwell time isn't used in sched scan or p2p find.
Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>