[Bluetooth] Make use of the default link policy settings

[Bluetooth] Make use of the default link policy settings

The Bluetooth specification supports the default link policy settings
on a per host controller basis. For every new connection the link
manager would then use these settings. It is better to use this instead
of bothering the controller on every connection setup to overwrite the
default settings.

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