Hi Claus,
the WiFi APIs and samples described in legato.io are generic… hardware agnostic.
To use it on a real hardware, the simplest is to use the reference design {mangOH + WiFi IoT Expansion Card}.
As pre-requisite, it will just request to use the latest release of WP8548/WP750x (http://source.sierrawireless.com/resources/legato/wpfirmwarerelease/) which is including a Linux Distribution with a native support of WiFi TI WL18xx chipset (the chipset on the WiFi IoT Expansion Card).
A tutorial to Get Started with WiFi IoT Expansion Card is planned to be published on http://mangoh.io very soon (~mid July).
BR,
Jacques