Added missing commas for mlir-nvidia buildbot.
This fixed the broken CMake arguments.

Patch by Christian Kühnel <kuhnel@google.com>

Differential Revision: https://reviews.llvm.org/D74699
diff --git a/buildbot/osuosl/master/config/builders.py b/buildbot/osuosl/master/config/builders.py
index 46dbf5d..295cd90 100644
--- a/buildbot/osuosl/master/config/builders.py
+++ b/buildbot/osuosl/master/config/builders.py
@@ -1031,12 +1031,12 @@
                         clean=True,
                         depends_on_projects=['llvm','mlir'],
                         extra_configure_args=[
-                            '-DLLVM_BUILD_EXAMPLES=ON'
-                            '-DLLVM_ENABLE_CXX1Y=Y '
-                            '-DLLVM_TARGETS_TO_BUILD="host;NVPTX"'
-                            '-DLLVM_ENABLE_PROJECTS=mlir'
-                            '-DMLIR_CUDA_RUNNER_ENABLED=1'
-                            '-DCMAKE_CUDA_COMPILER=/usr/local/cuda/bin/nvcc'
+                            '-DLLVM_BUILD_EXAMPLES=ON',
+                            '-DLLVM_ENABLE_CXX1Y=Y',
+                            '-DLLVM_TARGETS_TO_BUILD="host;NVPTX"',
+                            '-DLLVM_ENABLE_PROJECTS=mlir',
+                            '-DMLIR_CUDA_RUNNER_ENABLED=1',
+                            '-DCMAKE_CUDA_COMPILER=/usr/local/cuda/bin/nvcc',
                         ],
                         env={
                             'CC':'clang',