nl802154: add short address setting

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
nl802154: add support for setting cca ed level
nl802154: add support for setting lbt
mac802154: setting lbt mode while netif up
mac802154: increase tx queue like ethernet to 1000
mac802154: remove watchdog timeout

Should already be zero.
mac802154: remove unnecessary settings of type in sdata
ieee802154: 6lowpan: don't zero values twice
ieee802154: 6lowpan: add comment why we init rx in devinit
ieee802154: 6lowpan: improve hash generation
ieee802154: 6lowpan: handle error on receive
iface: add check for valid extended address
mac802154: don't change addresses while netif running