mac80211: define TDLS wider BW support bits

Allow a device to specify support for the TDLS wider-bandwidth feature.
Indicate this support during TDLS setup in the ext-capab IE and set an
appropriate station flag when our TDLS peer supports it.
This feature gives TDLS peers the ability to use a wider channel than
the base width of the BSS. For instance VHT capable TDLS peers connected
on a 20MHz channel can extend the channel to 80MHz, if regulatory
considerations allow it.

Do not cap the bandwidth of such stations by the current BSS channel width
in mac80211.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>