[rdk-b][mt7986][wifi-hal][Add get and set dfs enable and refactor dfs support]

[Description]
Add get and set dfs enable and refactor dfs support.
If set dfs disable, we would also set acs_exclude_dfs in hostapd config and possible channel should not reponse dfs channel.

[Release-log]
N/A

Change-Id: I679be1383263081e40d411015769061011735144
1 file changed