dm: spl: Don't set up device tree with of-platdata

When this feature is enabled, we should not access the device tree.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/spl.c b/common/spl/spl.c
index 5fbf101..59f41a1 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -202,7 +202,7 @@
 	gd->malloc_limit = CONFIG_SYS_MALLOC_F_LEN;
 	gd->malloc_ptr = 0;
 #endif
-	if (CONFIG_IS_ENABLED(OF_CONTROL)) {
+	if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) {
 		ret = fdtdec_setup();
 		if (ret) {
 			debug("fdtdec_setup() returned error %d\n", ret);