Update fx_importer.py to remove deprecated note

Remove note about method usage for HOPs.

Author: keshavvinayak01

python/torch_mlir/extras/fx_importer.py

@@ -997,8 +997,6 @@ def import_graph_module(
 
         TODO: This mechanism is deprecated by the `import_program` entry-point and
         it should be removed when no longer required for backwards compatibility.
-
-        Note: This method should only be used for HOPs.
         """
         # Store the mapping for this module itself (HOPs will need to look this up)
         module_id = id(gm)