Fix amd-smi CLI calls returning TypeError

$ amd-smi version
TypeError: unsupported operand type(s) for |: 'type' and 'type'

---------------
Python3 --versions lower than 3.10
do not support str | None

Using typing Optional and Union, we can create equivalent logic for
str | none
and
str | list | none

Change-Id: I1f4a7ab67333914b33639dc62652881e1127411e
Signed-off-by: Charis Poag <Charis.Poag@amd.com>

amdsmi_cli/amdsmi_parser.py

@@ -27,6 +27,8 @@ import os
 import sys
 import time
 import collections
+from typing import Optional
+from typing import Union
 
 from pathlib import Path
 
@@ -179,7 +181,7 @@ class AMDSMIParser(argparse.ArgumentParser):
 
         class AMDSMILimitArgs(argparse.Action):
             def __call__(self, parser: AMDSMIParser, namespace: argparse.Namespace,
-                         values: str | list | None, option_string: str | None = None) -> None:
+                         values: Union[str, list, None], option_string: Optional[str] = None) -> None:
                 # valid values
                 valid_clk_types = ('sclk', 'mclk')
                 valid_lim_types = ('min', 'max')