ipa: Skip doxygen parsing for pipeline-specific IPA headers

The pipeline-specific IPA headers are not part of the libcamera API,
they should thus be skipped when generating documentation. doxygen
doesn't complain currently due to the fact that types defined in those
headers are part of undocumented namespaces. In preparation for
documenting the libcamera namespace, make sure the headers don't get
parsed by doxygen.

Only vimc.h needs a header guard, as rkisp1.h uses the global namespace
and raspberrypi.h uses the undocumented libcamera::RPi namespace,
neither of which cause issues. Still, for consistency, add header guards
to all headers.

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

include/libcamera/ipa/raspberrypi.h

@@ -10,6 +10,8 @@
 #include <libcamera/control_ids.h>
 #include <libcamera/controls.h>
 
+#ifndef __DOXYGEN__
+
 namespace libcamera {
 
 namespace RPi {
@@ -66,4 +68,6 @@ static const ControlInfoMap Controls = {
 
 } /* namespace libcamera */
 
+#endif /* __DOXYGEN__ */
+
 #endif /* __LIBCAMERA_IPA_INTERFACE_RASPBERRYPI_H__ */