Add support for detecting USB devices in FreeBSD.

### Description

DiscImageChef should detect a USB device and get information from its descriptors.

### Exact command line used:

`DiscImageChef device-info -i /dev/da0`

### Expected behavior:
DiscImageChef retrieves and decodes USB descriptors and shows them to the user.

### Actual behavior:
Descriptors are not retrieved.