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/core/syscon-uclass.c b/drivers/core/syscon-uclass.c
index cb33fac..25fdb66 100644
--- a/drivers/core/syscon-uclass.c
+++ b/drivers/core/syscon-uclass.c
@@ -186,7 +186,7 @@
 U_BOOT_DRIVER(generic_syscon) = {
 	.name	= "syscon",
 	.id	= UCLASS_SYSCON,
-#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+#if CONFIG_IS_ENABLED(OF_REAL)
 	.bind           = dm_scan_fdt_dev,
 #endif
 	.of_match = generic_syscon_ids,