net: ieee802154: forbid monitor for add llsec devkey

net: ieee802154: forbid monitor for add llsec devkey

BugLink: https://bugs.launchpad.net/bugs/1926999
[ Upstream commit a347b3b394868fef15b16f143719df56184be81d ]

This patch forbids to add llsec devkey for monitor interfaces which we
don't support yet. Otherwise we will access llsec mib which isn't
initialized for monitors.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210405003054.256017-11-aahringo@redhat.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>