pipeline: v4l2_subdevice: Add color space to format string representation

To debug color issues in a pipeline it is necessary to know the color
space used. Therefore add the color space to the string representation
of V4L2SubdeviceFormat that is returned by toString() and operator<<().

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>

src/libcamera/v4l2_subdevice.cpp

@@ -949,6 +949,8 @@ std::ostream &operator<<(std::ostream &out, const V4L2SubdeviceFormat &f)
 	else
 		out << it->second.name;
 
+	out << "/" << ColorSpace::toString(f.colorSpace);
+
 	return out;
 }