clocksource: nspire: Fix compiler warning

CC      drivers/clocksource/zevio-timer.o
drivers/clocksource/zevio-timer.c:215:1: warning: comparison of distinct pointer types lacks a cast [enabled by default]
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/zevio-timer.c

@@ -212,4 +212,9 @@ static int __init zevio_timer_add(struct device_node *node)
 	return ret;
 }
 
-CLOCKSOURCE_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_add);
+static void __init zevio_timer_init(struct device_node *node)
+{
+	BUG_ON(zevio_timer_add(node));
+}
+
+CLOCKSOURCE_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_init);