cfg80211: introduce regulatory flags controlling bw

Allow setting bandwidth related regulatory flags. These flags are mapped
to the corresponding channel flags in the specified range.
Make sure the new flags are consulted when calculating the maximum
bandwidth allowed by a regulatory-rule.

Also allow propagating the GO_CONCURRENT modifier from a reg-rule to a
channel.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>