treewide: Use OF_REAL instead of !OF_PLATDATA

Now that we have a 'positive' Kconfig option, use this instead of the
negative one, which is harder to understand.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/timer/tsc_timer.c

@@ -479,7 +479,7 @@ static const struct timer_ops tsc_timer_ops = {
 	.get_count = tsc_timer_get_count,
 };
 
-#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+#if CONFIG_IS_ENABLED(OF_REAL)
 static const struct udevice_id tsc_timer_ids[] = {
 	{ .compatible = "x86,tsc-timer", },
 	{ }