add: info for 802.11s interface

additional information for commit 2a93c58042

package/gluon-core/files/usr/lib/lua/gluon/util.lua

@@ -79,6 +79,7 @@ end
 -- (2, n): client interface for the n'th radio
 -- (3, n): adhoc interface for n'th radio
 -- (4, 0): mesh VPN
+-- (5, n): mesh interface for n'th radio (802.11s)
 function generate_mac(f, i)
   local m1, m2, m3, m4, m5, m6 = string.match(sysconfig.primary_mac, '(%x%x):(%x%x):(%x%x):(%x%x):(%x%x):(%x%x)')
   m1 = nixio.bit.bor(tonumber(m1, 16), 0x02)