integrator: enable device tree

This enables the device tree library on the Integrator platforms
so we can pass a device tree when booting.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/include/configs/integrator-common.h b/include/configs/integrator-common.h
index 564b418..905b279 100644
--- a/include/configs/integrator-common.h
+++ b/include/configs/integrator-common.h
@@ -41,6 +41,7 @@
 
 #define CONFIG_CMDLINE_TAG		/* enable passing of ATAGs  */
 #define CONFIG_SETUP_MEMORY_TAGS
+#define CONFIG_OF_LIBFDT		/* enable passing a Device Tree */
 #define CONFIG_MISC_INIT_R		/* call misc_init_r during start up */
 
 /*