libcamera: tracing: Implement tracing infrastructure

Implement tracing infrastructure in libcamera. It takes .tp files, as
required by lttng, and generates a tracepoint header and C file, as lttng
requires. meson is updated accordingly to get it to compile with the
rest of libcamera. Update the documentation accordingly.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

meson_options.txt

@@ -28,6 +28,11 @@ option('test',
         type : 'boolean',
         description: 'Compile and include the tests')
 
+option('tracing',
+        type : 'feature',
+        value : 'auto',
+        description: 'Enable tracing (based on lttng)')
+
 option('v4l2',
         type : 'boolean',
         value : false,