Changed channel flags configuration to read the information from the driver

Changed channel flags configuration to read the information from the driver
(e.g., via driver_nl80211 when using mac80211) instead of using hostapd as
the source of the regulatory information (i.e., information from CRDA is
now used with mac80211); this allows 5 GHz channels to be used with hostapd
(if allowed in the current regulatory domain).