wifi: cfg80211: allow IR in 20 MHz configurations

wifi: cfg80211: allow IR in 20 MHz configurations

Some regulatory bodies doesn't allow IR (initiate radioation) on a
specific subband, but allows it for channels with a bandwidth of 20 MHz.
Add a channel flag that indicates that, and consider it in
cfg80211_reg_check_beaconing.

While on it, fix the kernel doc of enum nl80211_reg_rule_flags and
change it to use BIT().

Signed-off-by: Anjaneyulu <pagadala.yesu.anjaneyulu@intel.com>
Co-developed-by: Somashekhar Puttagangaiah <somashekhar.puttagangaiah@intel.com>
Signed-off-by: Somashekhar Puttagangaiah <somashekhar.puttagangaiah@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250308225541.d3ab352a73ff.I8a8f79e1c9eb74936929463960ee2a324712fe51@changeid
[fix typo]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>