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>
diff --git a/drivers/rtc/rtc-uclass.c b/drivers/rtc/rtc-uclass.c
index 321b873..e5ae6ea 100644
--- a/drivers/rtc/rtc-uclass.c
+++ b/drivers/rtc/rtc-uclass.c
@@ -177,7 +177,7 @@
 	.name		= "rtc",
 	.id		= UCLASS_RTC,
 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
-#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+#if CONFIG_IS_ENABLED(OF_REAL)
 	.post_bind	= dm_scan_fdt_dev,
 #endif
 };