Bluetooth: Audio: Enable controller extended and periodic adv for tests

The le-audio host shell enables extended advertising.  Therefore, for
the shell to be usable, extended and periodic advertising must also be
enabled for the controller.

The controller configuration are added to board-specific files for the
time being, as the advertising features are still experimental
upstream.

Signed-off-by: Asbjørn Sæbø <asbjorn.sabo@nordicsemi.no>