pipeline: ipa: raspberrypi: Switch to use C++17 features where possible

With the recent change to use C++17, the following code changes can be
made:
- Use C++17 [[fallthough]] attribute instead of /* Fall through */.
- Swap boost::any to std::any.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/pipeline/raspberrypi/raspberrypi.cpp

@@ -1494,7 +1494,7 @@ void RPiCameraData::handleState()
 		 * No break here, we want to try running the pipeline again.
 		 * The fallthrough clause below suppresses compiler warnings.
 		 */
-		/* Fall through */
+		[[fallthrough]];
 
 	case State::Idle:
 		tryRunPipeline();