stdlib: Remove unneeded imports in the gem5 Python Library

Change-Id: I6d4ccc4e18bd36d4a9dad9b6782ebcc0e64c4e44
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52203
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>

src/python/gem5/components/boards/simple_board.py

@@ -26,11 +26,8 @@
 
 from m5.objects import (
     AddrRange,
-    SrcClockDomain,
-    VoltageDomain,
     IOXBar,
     Port,
-    ClockDomain,
 )
 
 from .abstract_board import AbstractBoard

src/python/gem5/components/boards/test_board.py

@@ -25,9 +25,6 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 from m5.objects import (
-    SrcClockDomain,
-    ClockDomain,
-    VoltageDomain,
     Port,
     IOXBar,
     AddrRange,

src/python/gem5/components/boards/x86_board.py

@@ -59,8 +59,7 @@ from ..memory.abstract_memory_system import AbstractMemorySystem
 from ..cachehierarchies.abstract_cache_hierarchy import AbstractCacheHierarchy
 from ...utils.requires import requires
 
-import os
-from typing import List, Optional, Sequence
+from typing import List, Sequence
 
 
 class X86Board(AbstractBoard, KernelDiskWorkload):

src/python/gem5/components/processors/simple_processor.py

@@ -35,8 +35,6 @@ from .abstract_processor import AbstractProcessor
 from .cpu_types import CPUTypes
 from ..boards.abstract_board import AbstractBoard
 
-from typing import List
-
 
 class SimpleProcessor(AbstractProcessor):
     """

src/python/gem5/components/processors/simple_switchable_processor.py

@@ -32,8 +32,6 @@ from .switchable_processor import SwitchableProcessor
 
 from ...utils.override import *
 
-from m5.objects import KvmVM
-
 
 class SimpleSwitchableProcessor(SwitchableProcessor):
     """