am335x_evm: Only enable OF_CONTROL/OF_SEPARATE on VBOOT for now

We don't make use of the device tree otherwise yet (and will need to
think how to not break the current multi-board support) and this causes
further breakage with additional changes.

Signed-off-by: Tom Rini <trini@ti.com>
diff --git a/include/configs/am335x_evm.h b/include/configs/am335x_evm.h
index 5ae8c46..a48b386 100644
--- a/include/configs/am335x_evm.h
+++ b/include/configs/am335x_evm.h
@@ -22,10 +22,10 @@
 # define CONFIG_FIT
 # define CONFIG_TIMESTAMP
 # define CONFIG_LZO
-# define CONFIG_OF_CONTROL
-# define CONFIG_OF_SEPARATE
-# define CONFIG_DEFAULT_DEVICE_TREE am335x-boneblack
 # ifdef CONFIG_ENABLE_VBOOT
+#  define CONFIG_OF_CONTROL
+#  define CONFIG_OF_SEPARATE
+#  define CONFIG_DEFAULT_DEVICE_TREE am335x-boneblack
 #  define CONFIG_FIT_SIGNATURE
 #  define CONFIG_RSA
 # endif