[__timezone] add support for openwrt

cdist/conf/type/__timezone/gencode-remote

@@ -34,3 +34,12 @@ case "$os" in
       echo "echo \"$timezone_should\" > /etc/timezone"
    ;;
 esac
+
+case "$os" in
+    openwrt)
+        cat <<EOF
+			uci set system.@system[0].timezone="$timezone_should"
+			uci commit
+EOF
+   ;;
+esac

cdist/conf/type/__timezone/manifest

@@ -54,6 +54,9 @@ case "$os" in
                 --delimiter '=' \
                 --value "\"$timezone\""
         ;;
+    openwrt)
+        : # Uses gencode-remote
+        ;;
     *)
         echo "Your operating system ($os) is currently not supported by this type (${__type##*/})." >&2
         echo "Please contribute an implementation for it if you can." >&2