dts: Disable device tree for SPL on all boards

We plan to enable device tree in SPL by default. Before doing this,
explicitly disable it for all boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/origen_defconfig b/configs/origen_defconfig
index 3c59b9b..657ef7e 100644
--- a/configs/origen_defconfig
+++ b/configs/origen_defconfig
@@ -1,6 +1,7 @@
 CONFIG_ARM=y
 CONFIG_ARCH_EXYNOS=y
 CONFIG_TARGET_ORIGEN=y
+CONFIG_SPL_DISABLE_OF_CONTROL=y
 CONFIG_DEFAULT_DEVICE_TREE="exynos4210-origen"
 CONFIG_SPL=y
 CONFIG_CMD_SETEXPR=y