sys/v4l2/: add norm, channel and frequency properties.

sys/v4l2/: add norm, channel and frequency properties.

Original commit message from CVS:
2004-01-12  Benjamin Otte  <in7y118@public.uni-hamburg.de>

* sys/v4l2/gstv4l2element.c: (gst_v4l2element_class_init),
(gst_v4l2element_dispose), (gst_v4l2element_set_property),
(gst_v4l2element_get_property):
* sys/v4l2/v4l2_calls.c: (gst_v4l2_set_defaults), (gst_v4l2_open):
add norm, channel and frequency properties.
* sys/v4l2/gstv4l2tuner.c:
fixes for tuner interface changes
* sys/v4l2/gstv4l2element.h:
* sys/v4l2/gstv4l2src.c:
* sys/v4l2/gstv4l2src.h:
* sys/v4l2/v4l2src_calls.c:
* sys/v4l2/v4l2src_calls.h:
rework v4l2src to work with saa1734 cards and allow mmaped buffers.