nl80211: Allow more time for the initial scan with 6 GHz

nl80211: Allow more time for the initial scan with 6 GHz

The initial timeout of 10 seconds for the first scan before knowing
whether the driver reports scan completion events may not be sufficient
in cases where the driver ends up scanning a large number of channels.
In particular, this could be hit with 6 GHz support. Increase this
timeout when the driver indicates support for 6 GHz channels.

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