AEChannelInfo: Adjust the fixed layouts to ffmpeg order

This moves the LFE channel into the position where ffmpeg also has it. In fact I don't know of any sink that has this layout. So every time a user chooses fixed mode, the engine had to remap those layouts.

Changed Layouts: 5.1 and 7.1

This also fixes a pulseaudio mapping problems that it had with such "non pairwise" maps.