misc: Update black to process src/python/m5/ext/pystats

The exclusion in .pre-commit-config.yaml covered all files in
src/python/m5/ext. This excludes src/python/m5/exit/pystats, which we
want covered by black. This commit updates .pre-commit-config.yaml to
only exclude src/python/m5/ext/pyfdt.

This change also runs black on these files.

Change-Id: Iecff45ea2a27a37fc0d00b867d41300aad911c7a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/63711
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9fcca88..8cbc6af 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -44,7 +44,7 @@
     build/.*|
     src/systemc/ext/.*|
     src/systemc/tests/.*/.*|
-    src/python/m5/ext/.*|
+    src/python/m5/ext/pyfdt/.*|
     tests/.*/ref/.*
   )$
 
diff --git a/src/python/m5/ext/pystats/group.py b/src/python/m5/ext/pystats/group.py
index 55ec4b2..6e2da87 100644
--- a/src/python/m5/ext/pystats/group.py
+++ b/src/python/m5/ext/pystats/group.py
@@ -40,6 +40,7 @@
 from .statistic import Scalar, Statistic
 from .timeconversion import TimeConversion
 
+
 class Group(SerializableStat):
     """
     Used to create the heirarchical stats structure. A Group object contains a
@@ -70,7 +71,7 @@
     def children(
         self, predicate: Optional[Callable[[str], bool]] = None
     ) -> Iterator[Union["Group", Statistic]]:
-        """ Iterate through all of the children, optionally with a predicate
+        """Iterate through all of the children, optionally with a predicate
 
         ```
         >>> system.children(lambda _name: 'cpu' in name)
@@ -91,7 +92,7 @@
                 yield obj
 
     def find(self, name: str) -> Iterator[Union["Group", Statistic]]:
-        """ Find all stats that match the name
+        """Find all stats that match the name
 
         This function searches all of the "children" in this group. It yields
         the set of attributes (children) that have the `name` as a substring.
@@ -117,7 +118,7 @@
     def find_re(
         self, regex: Union[str, Pattern]
     ) -> Iterator[Union["Group", Statistic]]:
-        """ Find all stats that match the name
+        """Find all stats that match the name
 
         This function searches all of the "children" in this group. It yields
         the set of attributes (children) that have the `name` mathing the
diff --git a/src/python/m5/ext/pystats/serializable_stat.py b/src/python/m5/ext/pystats/serializable_stat.py
index 3ad9b50..c4de181 100644
--- a/src/python/m5/ext/pystats/serializable_stat.py
+++ b/src/python/m5/ext/pystats/serializable_stat.py
@@ -30,6 +30,7 @@
 
 from .storagetype import StorageType
 
+
 class SerializableStat:
     """
     Classes which inherit from SerializableStat can be serialized as JSON
diff --git a/src/python/m5/ext/pystats/simstat.py b/src/python/m5/ext/pystats/simstat.py
index 3cea133..bab47cc 100644
--- a/src/python/m5/ext/pystats/simstat.py
+++ b/src/python/m5/ext/pystats/simstat.py
@@ -32,6 +32,7 @@
 from .statistic import Statistic
 from .timeconversion import TimeConversion
 
+
 class SimStat(SerializableStat):
     """
     Contains all the statistics for a given simulation.