headers: Add missing symbols in l2cmn.h
This also fixes the following error.
wlanapi.h:18:44: note: expanded from macro 'WLAN_NOTIFICATION_SOURCE_ALL'
^
Signed-off-by: Biswapriyo Nath <nathbappai@gmail.com>
Signed-off-by: LIU Hao <lh_mouse@126.com>