Fix incorrect colorspace in MMAL renderer

app/streaming/video/ffmpeg-renderers/mmal.h

@@ -17,6 +17,7 @@ public:
     virtual enum AVPixelFormat getPreferredPixelFormat(int videoFormat) override;
     virtual bool needsTestFrame() override;
     virtual int getRendererAttributes() override;
+    virtual int getDecoderColorspace() override;
 
 private:
     static void InputPortCallback(MMAL_PORT_T* port, MMAL_BUFFER_HEADER_T* buffer);