[media] v4l2-ioctl.h: document the remaining functions

There are several undocumented functions here; document them.

While here, make checkpatch.pl happy.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/conf_nitpick.py

@@ -96,5 +96,6 @@ nitpick_ignore = [
     ("c:type", "__user"),
     ("c:type", "usb_device"),
     ("c:type", "usb_interface"),
+    ("c:type", "v4l2_std_id"),
     ("c:type", "video_system_t"),
 ]