patman: Convert camel case in gitutil.py

Convert this file to snake case and update all files which use it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/patman/patchstream.py b/tools/patman/patchstream.py
index 387e9de..9b32fd4 100644
--- a/tools/patman/patchstream.py
+++ b/tools/patman/patchstream.py
@@ -698,7 +698,7 @@
     Returns
         str: String containing the contents of the git log
     """
-    params = gitutil.LogCmd(commit_range, reverse=True, count=count,
+    params = gitutil.log_cmd(commit_range, reverse=True, count=count,
                             git_dir=git_dir)
     return command.run_pipe([params], capture=True).stdout