[media] vpif_capture.c: v4l2_device_register() is called too late in vpif_probe()
The function v4l2_device_register() is called too late in vpif_probe().
This meant that vpif_obj.v4l2_dev is accessed before it is initialized
which caused a crash.
This used to work in the past, but video_register_device() is now actually
using the v4l2_dev pointer.
Note that vpif_display.c doesn't have this bug, there v4l2_device_register()
is called at the beginning of vpif_probe.