v4l2: v4l2_camera: Add isRunning()

Add a method isRunning() to V4L2Camera so that V4L2CameraProxy can use
it for checks.

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

src/v4l2/v4l2_camera.cpp

@@ -227,3 +227,8 @@ int V4L2Camera::qbuf(unsigned int index)
 
 	return 0;
 }
+
+bool V4L2Camera::isRunning()
+{
+	return isRunning_;
+}

src/v4l2/v4l2_camera.h

@@ -57,6 +57,8 @@ public:
 
 	int qbuf(unsigned int index);
 
+	bool isRunning();
+
 	Semaphore bufferSema_;
 
 private: