openntpd: style fix - don't capitalize in menu

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/openntpd/Config.in

@@ -1,5 +1,5 @@
 config BR2_PACKAGE_OPENNTPD
-	bool "OpenNTPD"
+	bool "openntpd"
 	help
 	     OpenNTPD is an easy to use implementation of the Network Time
 	     Protocol. It provides the ability to sync the local clock