mac80211: add MESH IE in the correct order

VHT MESH support was added, but the order of the IEs
wasn't enforced. Fix that.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>