wifi: mac80211_hwsim: add incumbent signal interference detection support

wifi: mac80211_hwsim: add incumbent signal interference detection support

Add a debugfs 'simulate_incumbent_signal_interference' with custom
file_operations and a .write that accepts "<freq_mhz> <bitmap>". The
handler selects the 6 GHz chanctx whose primary 20 MHz center matches
<freq_mhz> and reports the event via cfg80211_incumbent_signal_notify().
The bitmap marks affected 20 MHz segments within the current chandef
(lowest bit = lowest segment)

Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
Signed-off-by: Amith A <amith.a@oss.qualcomm.com>
Link: https://patch.msgid.link/20260306060927.504567-2-amith.a@oss.qualcomm.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>