doc/conf.py: update copyright to 2022

Update copyright time frame.

Signed-off-by: Dan Kalowsky <[email protected]>

Author: dkalowsk

doc/conf.py

@@ -36,7 +36,7 @@
 # -- Project --------------------------------------------------------------
 
 project = "Zephyr Project"
-copyright = "2015-2021 Zephyr Project members and individual contributors"
+copyright = "2015-2022 Zephyr Project members and individual contributors"
 author = "The Zephyr Project Contributors"
 
 # parse version from 'VERSION' file