For some series with lots of changes it is annoying that duplicate change
log items are not caught. It is also helpful sometimes to sort the change
logs.

Add a Series-process-log tag to enable this, which can be placed in a
commit to control this.

The change to the Cc: line is to fix a checkpatch warning.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>