Original commit message from CVS:
2007-06-06  Andy Wingo  <wingo@pobox.com>

* sys/v4l2/v4l2src_calls.c (gst_v4l2src_probe_caps_for_format)
(gst_v4l2src_probe_caps_for_format_and_size): Only probe for
format and size if the ioctls are defined; should fix compilation
on Linux < 2.16.19.