Test build with microphone and camera support

Add support for both the rear OV13858 and front IMX681 camera.

To use the cameras, one does need a more up to date version of libcamera than e.g. the ubuntu apt sources provide. Libcamera can be found in: https://github.com/libcamera-org/libcamera. This has been developed with commit b18132713165210d45d66d54e7ae6086a021a47e. When installed, using cam -l should show both cameras, and qcam should be able to view a video stream of both. Please note, that the image quality will be terrible, as the driver contains no optimization yet.