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/colibri_t20_defconfig b/configs/colibri_t20_defconfig
index 6ac29d7..85956c5 100644
--- a/configs/colibri_t20_defconfig
+++ b/configs/colibri_t20_defconfig
@@ -52,3 +52,4 @@
 CONFIG_DM_VIDEO=y
 CONFIG_VIDEO_TEGRA20=y
 CONFIG_CONSOLE_SCROLL_LINES=10
+CONFIG_OF_LIBFDT_OVERLAY=y