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/ads1x15/ads1015.hpp

@@ -82,6 +82,8 @@ namespace upm {
    *
    * @image html ads1015.jpg
    * @snippet ads1x15.cxx Interesting
+   * @snippet ads1x15-ads1015.cxx Interesting
+   * @snippet ads1x15-adc-sensor.cxx Interesting
    */
     class ADS1015 : public ADS1X15, public IADC {