clearfog: Ensure that we have host `dtc`

...because U-Boot's build needs it. I made a mistake, my laptop had it
installed for $reasons.

Change-Id: Ibe221ca31d7b50f05f740098b241cea0390843bd
diff --git a/configs/czechlight_clearfog_defconfig b/configs/czechlight_clearfog_defconfig
index f051c82..ae8668e 100644
--- a/configs/czechlight_clearfog_defconfig
+++ b/configs/czechlight_clearfog_defconfig
@@ -47,6 +47,7 @@
 BR2_TARGET_UBOOT_PATCH="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/patches/u-boot/boot.patch"
 BR2_TARGET_UBOOT_BOARD_DEFCONFIG="clearfog"
 BR2_TARGET_UBOOT_CONFIG_FRAGMENT_FILES="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/uboot.fragment"
+BR2_TARGET_UBOOT_NEEDS_DTC=y
 # BR2_TARGET_UBOOT_FORMAT_BIN is not set
 BR2_TARGET_UBOOT_FORMAT_CUSTOM=y
 BR2_TARGET_UBOOT_FORMAT_CUSTOM_NAME="u-boot-spl.kwb"