patman: Add a Series-patchwork-url option

Add a commit tag to allow the Patchwork URL to be specified in a commit.
This can be handy for when you submit code to multiple projects but don't
want to use the -p option.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/patman/control.py b/tools/patman/control.py
index a3c50cd..2330682 100644
--- a/tools/patman/control.py
+++ b/tools/patman/control.py
@@ -196,7 +196,8 @@
         force (bool): With dest_branch, force overwriting an existing branch
         show_comments (bool): True to display snippets from the comments
             provided by reviewers
-        url (str): URL of patchwork server, e.g. 'https://patchwork.ozlabs.org'
+        url (str): URL of patchwork server, e.g. 'https://patchwork.ozlabs.org'.
+            This is ignored if the series provides a Series-patchwork-url tag.
 
     Raises:
         ValueError: if the branch has no Series-link value
@@ -225,6 +226,10 @@
     if not found:
         raise ValueError('Series-links has no current version (without :)')
 
+    # Allow the series to override the URL
+    if 'patchwork_url' in series:
+        url = series.patchwork_url
+
     # Import this here to avoid failing on other commands if the dependencies
     # are not present
     from patman import status