binman: Add support for outputing a map file

It is useful to be able to see a list of regions in each image produced by
binman. Add a -m option to output this information in a '.map' file
alongside the image file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/control.py b/tools/binman/control.py
index bc8ed8e..9243472 100644
--- a/tools/binman/control.py
+++ b/tools/binman/control.py
@@ -112,6 +112,8 @@
                 image.ProcessEntryContents()
                 image.WriteSymbols()
                 image.BuildImage()
+                if options.map:
+                    image.WriteMap()
         finally:
             tools.FinaliseOutputDir()
     finally: