pca9685: Patching up doxygen comments

Signed-off-by: John Van Drasek <john.r.van.drasek@intel.com>

src/pca9685/pca9685.h

@@ -44,7 +44,7 @@ namespace upm {
    * @ingroup adafruit i2c led motor
    */
   /**
-   * @library libupm-pca9685
+   * @library pca9685
    * @sensor pca9685
    * @comname 16 Channel, 12 bit pwm LED controller
    * @type led motor