python: Apply Black formatter to Python files

The command executed was `black src configs tests util`.

Change-Id: I8dfaa6ab04658fea37618127d6ac19270028d771
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47024
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/systemc/python/tlm.py

@@ -27,7 +27,9 @@ import _m5.systemc
 
 from _m5.systemc import tlm_global_quantum
 
+
 def tlm_global_quantum_instance():
     return tlm_global_quantum.instance()
 
-__all__ = [ 'tlm_global_quantum_instance' ]
+
+__all__ = ["tlm_global_quantum_instance"]