common: fix title page

Sphinx changed the default behavior of maketitle. Provide our
own rtemsmaketitle command and use it instead.

common/conf.py

@@ -193,6 +193,7 @@ latex_elements = {
 \newcommand{\rtemscopyright}{%s}
 \usepackage{rtemsstyle}
 ''' % (copyright),
+    'maketitle': r'\rtemsmaketitle',
     'parsedliteralwraps': True,
 }