doc: update version number

Signed-off-by: Jingru Wang <jingru@synopsys.com>

Author: wangnuannuan

doc/documents/conf.py

@@ -61,7 +61,7 @@
 
 # General information about the project.
 project = u'embARC'
-copyright = u'2019, Synopsys'
+copyright = u'2021, Synopsys'
 author = u'Synopsys'
 today_fmt = '%Y'
 
@@ -70,9 +70,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'2019.06'
+version = u'2021.09'
 # The full version, including alpha/beta/rc tags.
-release = u'2019.06'
+release = u'2021.09'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.