binman: Add a command to generate bintool docs

Each bintool has some documentation which can be useful for the user.
Add a new command that collects this and writes it into a .rst file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/control.py b/tools/binman/control.py
index bbd7773..2daad05 100644
--- a/tools/binman/control.py
+++ b/tools/binman/control.py
@@ -140,7 +140,7 @@
 
     Args:
         modules: List of Module objects to get docs for
-        test_missing: Used for testing only, to force an entry's documeentation
+        test_missing: Used for testing only, to force an entry's documentation
             to show as missing even if it is present. Should be set to None in
             normal use.
     """
@@ -148,6 +148,18 @@
     Entry.WriteDocs(modules, test_missing)
 
 
+def write_bintool_docs(modules, test_missing=None):
+    """Write out documentation for all bintools
+
+    Args:
+        modules: List of Module objects to get docs for
+        test_missing: Used for testing only, to force an entry's documentation
+            to show as missing even if it is present. Should be set to None in
+            normal use.
+    """
+    bintool.Bintool.WriteDocs(modules, test_missing)
+
+
 def ListEntries(image_fname, entry_paths):
     """List the entries in an image