[mlir] Change default NVVM compilation to fatbin from bin (#70052)

Change the NVVM assembly to `fatbin` as it is executable for multiple
architectures. Using `bin` caused test errors at runtime in the test
systems.

Author: grypp

mlir/test/lib/Dialect/GPU/TestLowerToNVVM.cpp

@@ -60,7 +60,7 @@ struct TestLowerToNVVMOptions
   PassOptions::Option<std::string> cubinFormat{
       *this, "cubin-format",
       llvm::cl::desc("Compilation format to use to serialize to cubin."),
-      llvm::cl::init("bin")};
+      llvm::cl::init("fatbin")};
   PassOptions::Option<int> optLevel{
       *this, "opt-level",
       llvm::cl::desc("Optimization level for NVVM compilation"),
@@ -156,4 +156,4 @@ void registerTestLowerToNVVM() {
 }
 } // namespace test
 } // namespace mlir
-#endif // MLIR_CUDA_CONVERSIONS_ENABLED
+#endif // MLIR_CUDA_CONVERSIONS_ENABLED