Boost.Chrono: Added Header Only category

[SVN r68033]

status/explicit-failures-markup.xml

@@ -487,12 +487,14 @@
                 The compiler does not support features that are essential for the library.
             </note>
         </mark-unusable>
-        <test name="*_fail" category="Fail">
+        <test name="*_header" category="Header Only">
         </test>
         <test name="*_static" category="Static Link">
         </test>
         <test name="*_shared" category="Shared Link">
         </test>
+        <test name="*_fail" category="Compile Diagnostic Required">
+        </test>
       
     </library>