Forgotten oma docs stuff

Originally committed as revision 13766 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/general.texi

@@ -139,6 +139,8 @@ different game cutscenes repacked for use with ScummVM.
 @tab Interchange File Format
 @item BFI @tab    @tab X
 @tab Brute Force & Ignorance, used in Flash Traffic: City of Angels
+@item OMA @tab    @tab X
+@tab Audio format used in Sony Sonic Stage and Sony Vegas
 @end multitable
 
 @code{X} means that encoding (resp. decoding) is supported.