Fix reference to PCM codec registration

Author: chrisn

codec_registry.src.html

@@ -151,7 +151,7 @@
     <td>Linear PCM</td>
     <td>[Linear PCM WebCodecs
       Registration](https://www.w3.org/TR/webcodecs-pcm-codec-registration/)
-    [[WEBCODECS-ALAW-CODEC-REGISTRATION]]</td>
+    [[WEBCODECS-PCM-CODEC-REGISTRATION]]</td>
   </tr>
 </table>