[css-color-5][editorial] add wpt

Author: svgeesus

css-color-5/Overview.bs

@@ -2670,6 +2670,8 @@ depends on the color space specified with "in".
 
 <wpt>
 	parsing/color-valid-color-mix-function.html
+	color-mix-currentcolor-visited-getcomputedstyle.html
+	color-mix-currentcolor-visited.html
 </wpt>
 
 The <em>minimum</em> precision for round-tripping