[RFC] hostapd: allow configuring driver to VHT

[Johannes Berg]

>  int hostapd_set_freq(struct hostapd_data *hapd, int mode, int freq,
> -		     int channel, int ht_enabled, int sec_channel_offset)
> +		     int channel, int ht_enabled, int vht_enabled,
> +		     int sec_channel_offset, int vht_oper_chwidth,
> +		     int center_segment0, int center_segment1)

Note I'm just changing this here, and only validate that the HT settings
and VHT settings are compatible.

This probably isn't the right place for this though, I think we should
probably check these things in src/ap/hw_features.c. If anybody wants to
work on that ... I have a bunch of other more important things to worry
about, like parsing the VHT operation IE in mac80211 :-)

johannes