v4l2: Track /dev/video* to triggered required probe
v4l2: Track /dev/video* to triggered required probe

If something in /dev/video* get added, removed or replaced, we need to
probe the devices again in order to ensure the dynamic devices are up to
date.

NOTE This patch shows a nees for a PREFIX flag.

[endlessm/eos-shell/issues/5981]

ndufresne/gst-plugins-good,ndufresne/gst-plugins-good,ndufresne/gst-plugins-good,ndufresne/gst-plugins-good