Doc: Change wikipedia's URL from http to https

Recently wikipedia announced to secure access to the servers.
Now all http access re-route to https.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt
index 92e68bc..5737e35 100644
--- a/Documentation/input/rotary-encoder.txt
+++ b/Documentation/input/rotary-encoder.txt
@@ -33,7 +33,7 @@
 	          one step (half-period mode)
 
 For more information, please see
-	http://en.wikipedia.org/wiki/Rotary_encoder
+	https://en.wikipedia.org/wiki/Rotary_encoder
 
 
 1. Events / state machine