OWE: Optimize transition mode scan to use known channels

OWE: Optimize transition mode scan to use known channels

If the currently available scan results include OWE transition mode BSS
with an unknown SSID, optimize the following scan for OWE to use only
the channels on which a known transition mode BSS has been seen.

This is needed to be able to remove the design that updates BSS entries
with the learned OWE SSID in manner that does not result in regression
to scanning latencies.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>