doc-rst: linux_tv: supress lots of warnings

The c language parser checks if there are duplicated object
definitions. That causes lots of warnings like:
	WARNING: duplicate C object description of ioctl

Let's remove those by telling Sphinx that the language for
those objects are c++. The look of the descriptions will
be close, and the warnings will be gone.

Please notice that we had to keep a few of them as C, as
the c++ parser seems to be broken when it finds an enum.

Yet, this reduced from 219 warnings to 143, with is
a good thing.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/Documentation/linux_tv/media/v4l/vidioc-enuminput.rst b/Documentation/linux_tv/media/v4l/vidioc-enuminput.rst
index 131f331..3b0577a 100644
--- a/Documentation/linux_tv/media/v4l/vidioc-enuminput.rst
+++ b/Documentation/linux_tv/media/v4l/vidioc-enuminput.rst
@@ -14,7 +14,7 @@
 Synopsis
 ========
 
-.. c:function:: int ioctl( int fd, int request, struct v4l2_input *argp )
+.. cpp:function:: int ioctl( int fd, int request, struct v4l2_input *argp )
 
 Arguments
 =========