toradex apalis/colibri: add device tree overlay support

Device tree overlays might prove useful in the future, enable it
by default on all Toradex modules.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Max Krummenacher <max.krummenacher@toradex.com>
diff --git a/configs/apalis_imx6_defconfig b/configs/apalis_imx6_defconfig
index dc10e41..3940dac 100644
--- a/configs/apalis_imx6_defconfig
+++ b/configs/apalis_imx6_defconfig
@@ -48,4 +48,5 @@
 CONFIG_G_DNL_VENDOR_NUM=0x1b67
 CONFIG_G_DNL_PRODUCT_NUM=0x4000
 CONFIG_OF_LIBFDT=y
+CONFIG_OF_LIBFDT_OVERLAY=y
 # CONFIG_EFI_LOADER is not set