libcamera: v4l2_controls: Add min and max to V4L2ControlInfo

Add min() and max() methods to V4L2ControlInfo to report the control's
minimum and maximum value respectively.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

src/libcamera/include/v4l2_controls.h

@@ -28,11 +28,17 @@ public:
 	size_t size() const { return size_; }
 	const std::string &name() const { return name_; }
 
+	int64_t min() const { return min_; }
+	int64_t max() const { return max_; }
+
 private:
 	unsigned int id_;
 	unsigned int type_;
 	size_t size_;
 	std::string name_;
+
+	int64_t min_;
+	int64_t max_;
 };
 
 class V4L2Control