[css-easing-1] Use CSS-VALUES-3 reference consistently

Author: birtles

css-easing-1/Overview.bs

@@ -149,7 +149,7 @@ are restricted to the range [0, 1].
 </figure>
 
 A <a>cubic B&eacute;zier easing function</a> has the following syntax
-(using notation from [[!CSS3VAL]]):
+(using notation from [[!CSS-VALUES-3]]):
 
 <div class="prod"><dfn type>&lt;cubic-bezier-easing-function&gt;</dfn> =
   ''ease'' | ''ease-in'' | ''ease-out'' | ''ease-in-out'' |