updated summation point to reflect the changes Nicolas made

Author: AndrewBMadison

Simulator/Vertices/Neuro/AllSpikingNeurons.h

@@ -159,6 +159,9 @@ struct AllSpikingNeuronsDeviceProperties : public AllVerticesDeviceProperties {
    ///  On the next advance cycle, vertices add the values stored in their corresponding
    ///  summation points to their Vm and resets the summation points to zero
    BGFLOAT *summationPoints_;
+   #ifdef VALIDATION_MODE
+   BGFLOAT *spValidation_;
+   #endif
 };
 #endif   // defined(USE_GPU)