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/arch/arm/Kconfig b/arch/arm/Kconfig
index 2985e6e..fd47e60 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -668,6 +668,7 @@
 	select SUPPORT_SPL
 	select SPL
 	select OF_CONTROL
+	select SPL_DISABLE_OF_CONTROL
 	select CPU_V7
 	select DM
 	select DM_SPI_FLASH
@@ -794,6 +795,7 @@
 	select DM
 	select DM_SERIAL
 	select DM_I2C
+	select SPL_DISABLE_OF_CONTROL
 	help
 	  Support for UniPhier SoC family developed by Socionext Inc.
 	  (formerly, System LSI Business Division of Panasonic Corporation)