base, sim: Make ByteOrder into a ScopedEnum accessible to Python

There is currently no good way of passing a byte order as a Param
since the ByteOrder type is defined in C++. Make this into a generated
ScopedEnum that can be used in Params.

Change-Id: I990f402340c17c4e0799de57df19516ae61794d4
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33174
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>

src/python/m5/params.py

@@ -1513,6 +1513,14 @@ class ScopedEnum(Enum):
     # If not None, use this as the enum name rather than this class name
     enum_name = None
 
+class ByteOrder(ScopedEnum):
+    """Enum representing component's byte order (endianness)"""
+
+    vals = [
+        'big',
+        'little',
+    ]
+
 # how big does a rounding error need to be before we warn about it?
 frequency_tolerance = 0.001  # 0.1%