wifi: cfg80211: save power spectral density(psd) of regulatory rule

6 GHz regulatory domains introduces Power Spectral Density (PSD).
The PSD value of the regulatory rule should be taken into effect
for the ieee80211_channels falling into that particular regulatory
rule. Save the values in the channel which has PSD value and add
nl80211 attributes accordingly to handle it.

Co-developed-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Link: https://lore.kernel.org/r/20230914082026.3709-1-quic_wgong@quicinc.com


[use hole in chan flags, reword docs]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>