sys/v4l2/gstv4l2element.h: Yet Another Hack (tm) for kernel header borkedness.

sys/v4l2/gstv4l2element.h: Yet Another Hack (tm) for kernel header borkedness.

Original commit message from CVS:
* sys/v4l2/gstv4l2element.h:
Yet Another Hack (tm) for kernel header borkedness.
* sys/v4l2/gstv4l2src.c: (gst_v4l2src_init),
(gst_v4l2src_v4l2fourcc_to_caps), (gst_v4l2_fourcc_from_structure),
(gst_v4l2src_link), (gst_v4l2src_getcaps),
(gst_v4l2src_change_state):
* sys/v4l2/gstv4l2src.h:
* sys/v4l2/v4l2src_calls.c: (gst_v4l2src_capture_init),
(gst_v4l2src_capture_start), (gst_v4l2src_capture_stop):
Fix caps, keep track of state, work.