clearfog: Don't forget to enable this board-specific overlay

Change-Id: I89e9eca5ba53e00a53de9b39e31a9de235cc6223
diff --git a/configs/czechlight_clearfog_defconfig b/configs/czechlight_clearfog_defconfig
index 0ba21a4..b19ab3c 100644
--- a/configs/czechlight_clearfog_defconfig
+++ b/configs/czechlight_clearfog_defconfig
@@ -12,7 +12,7 @@
 BR2_TARGET_GENERIC_PASSWD_SHA256=y
 BR2_INIT_SYSTEMD=y
 # BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW is not set
-BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/overlay/"
+BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/overlay/ $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/overlay/"
 BR2_ROOTFS_POST_BUILD_SCRIPT="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/post-build.sh"
 BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
 BR2_ROOTFS_POST_SCRIPT_ARGS="-c $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/genimage.cfg"