Added information about added GLX_SGI_make_current_read support

docs/relnotes-6.5.2.html

@@ -43,6 +43,13 @@ copy texturing).
 <li>New Intel i965 DRI driver
 <li>New <code>minstall</code> script to replace normal install program
 <li>Faster fragment program execution in software
+<li>Added (or fixed) support for <a href="http://www.opengl.org/registry/specs/SGI/make_current_read.txt">
+    GLX_SGI_make_current_read</a> to the following drivers:</li>
+    <ul>
+    <li>radeon</li>
+    <li>savage</li>
+    <li>mga</li>
+    </ul>
 </ul>
 
 <h2>Bug fixes</h2>