libcamera: camera_lens: Add function to fetch subdev controls

Add a function to the CameraLens class to fetch the V4L2 controls
for its V4L2 subdev

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/internal/camera_lens.h

@@ -12,6 +12,8 @@
 #include <libcamera/base/class.h>
 #include <libcamera/base/log.h>
 
+#include <libcamera/controls.h>
+
 namespace libcamera {
 
 class MediaEntity;
@@ -28,6 +30,8 @@ public:
 
 	const std::string &model() const { return model_; }
 
+	const ControlInfoMap &controls() const;
+
 protected:
 	std::string logPrefix() const override;