I doubt that enabling/disabling fbc will help you, but I'm unsure as to why you are unsure where you have to add that. The wiki contains both an example file (if the wiki talks about a file and it's contents, the usual thing you should do if that file isn't present, is to create it with the mentioned content) as well as links on how to specify that same option in your kernel parameters. It isn't going to be set if you do not consciously set it yourself (or rather it is set to a default value that varies by hardware and how safe the developer consider the option to be for the hardware).