Add support for using an UART instead of the native controller. This is
accomplished with a custom DTS overlay for the tests that require it.
Signed-off-by: Johan Hedberg <johan.hedberg@gmail.com>
Add a basic connection test between two devices,
in which the controllers are in separate nrf52_bsim devices
connected over UART to the devices running the host+app.
The controllers are running the HCI UART async sample.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>