mac802154: Trace the registration of new PANs

Add an internal trace when valid beacons are received.

Signed-off-by: David Girault <david.girault@qorvo.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20221129135535.532513-3-miquel.raynal@bootlin.com


Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>