Bluetooth: Fix authentication requirements for L2CAP security check

The L2CAP layer can trigger the authentication via an ACL connection or
later on to increase the security level. When increasing the security
level it didn't use the same authentication requirements when triggering
a new ACL connection. Make sure that exactly the same authentication
requirements are used. The only exception here are the L2CAP raw sockets
which are only used for dedicated bonding.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>