GPU: Fix kernel file include order, must follow template specialization usage

Author: davidrohr

GPU/GPUTracking/kernels.cmake

@@ -19,7 +19,7 @@ o2_gpu_kernel_file_list(TPCSECTORDATA TPCTRACKER GPUTPCTrackingData.cxx)
 o2_gpu_kernel_file_list(TPCOCCUPANCY GPUTPCClusterOccupancyMap.cxx)
 o2_gpu_kernel_file_list(TPCDEDX GPUdEdx.cxx)
 o2_gpu_kernel_file_list(MATLUT MatLayerCylSet.cxx MatLayerCyl.cxx Ray.cxx)
-o2_gpu_kernel_file_list(TPCMERGER ERRORS GPUTPCGMMerger.cxx GPUTPCGMSectorTrack.cxx GPUTPCGMTrackParam.cxx GPUTPCGMPhysicalTrackModel.cxx GPUTPCGMPropagator.cxx)
+o2_gpu_kernel_file_list(TPCMERGER ERRORS GPUTPCGMSectorTrack.cxx GPUTPCGMMerger.cxx GPUTPCGMTrackParam.cxx GPUTPCGMPhysicalTrackModel.cxx GPUTPCGMPropagator.cxx)
 o2_gpu_kernel_file_list(O2PROPAGATOR TrackParametrization.cxx TrackParametrizationWithError.cxx Propagator.cxx TrackLTIntegral.cxx)
 o2_gpu_kernel_file_list(TPCCOMPRESSION GPUTPCCompressionTrackModel.cxx)
 o2_gpu_kernel_file_list(TPCDECOMPRESSION GPUTPCCompressionTrackModel.cxx ERRORS)