removing Platform enum from converter_utils.py

Author: apbose

py/torch_tensorrt/dynamo/conversion/converter_utils.py

@@ -11,7 +11,6 @@
 from torch.fx.node import Argument, Target
 from torch.fx.passes.shape_prop import TensorMetadata
 from torch_tensorrt import _enums
-from torch_tensorrt._enums import Platform
 from torch_tensorrt.dynamo._settings import CompilationSettings
 from torch_tensorrt.dynamo._SourceIR import SourceIR
 from torch_tensorrt.dynamo.conversion._ConversionContext import ConversionContext