snippet: Updated all snippet tags

Ensure all src C++ headers which have corresponding C++ examples have
doxygen tags which point to those examples.  Some were missing, some
were invalid, some needed to be updated to match the new example names.

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/grove/grovebutton.hpp

@@ -49,7 +49,7 @@ namespace upm {
  * Basic UPM module for the Grove button
  *
  * @image html grovebutton.jpg
- * @snippet grovebutton.cxx Interesting
+ * @snippet grove-grovebutton.cxx Interesting
  */
 class GroveButton: public Grove {
     public: