Option to hide non-DEDICATED devices

[baryluk]

It would be nice to be able to change the order of devices, or even hide non-DEDICATED devices.

Something like DEVICE_CHOOSER_DEDICATED_ONLY=1.

This way it might be possible to get rid of device index in a lot of use cases, making it easier to users, as well making it more deterministic (i.e. in case devices are reordered due to some other reason, like directory entries being scanned by the loader in different order, or similar).