python: Replace 'getargspec' with 'signature' in SimObject.py

In Python 3.11 'inspect.getargspec' has been removed. It has been
marked for deprecation since 3.5. The SimObject.py class has therefore
been rewritten to use 'inspect.signature' instead.

Change-Id: I9efd831e05e0b1619f366ffe722abb0a072fd519
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/68817
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed