Revert "OpenCL: Enable 64bit integer atomics"

This reverts commit a53a04b.

Author: fweig

GPU/GPUTracking/Base/opencl/GPUReconstructionOCL.cl

@@ -22,8 +22,6 @@
   #endif
   #pragma OPENCL EXTENSION cl_khr_fp64 : enable // Allow double precision variables
   #pragma OPENCL EXTENSION cl_khr_fp16 : enable // Allow half precision
-  #pragma OPENCL EXTENSION cl_khr_int64_base_atomics : enable // Allow 64bit integer atomics
-  #pragma OPENCL EXTENSION cl_khr_int64_extended_atomics : enable
   #ifdef __clang__
     #pragma OPENCL EXTENSION cl_clang_storage_class_specifiers : enable          //
     #pragma OPENCL EXTENSION __cl_clang_function_pointers : enable               // Allow function pointers

GPU/GPUTracking/TPCClusterFinder/GPUTPCCFCheckPadBaseline.cxx

@@ -579,5 +579,9 @@ GPUd() void GPUTPCCFHIPClusterizer::Thread<0>(int32_t nBlocks, int32_t nThreads,
     }
   }
 
-  CAMath::AtomicAdd((unsigned long long*)&clusterer.mPmemory->counters.nClusters, (unsigned long long)nCreatedClusters);
+#if defined(GPUCA_GPUCODE) && (defined(__CUDACC__) || defined(__HIPCC__))
+  CAMath::AtomicAdd(reinterpret_cast<unsigned long long*>(&clusterer.mPmemory->counters.nClusters), (unsigned long long)nCreatedClusters);
+#else
+  CAMath::AtomicAdd(&clusterer.mPmemory->counters.nClusters, nCreatedClusters);
+#endif
 }