configs/freescale_imx6sxsabresd: U-Boot needs host-dtc

Fixes:

  https://gitlab.com/buildroot.org/buildroot/-/jobs/55306823

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/freescale_imx6sxsabresd_defconfig

@@ -39,3 +39,4 @@ BR2_TARGET_UBOOT_CUSTOM_GIT=y
 BR2_TARGET_UBOOT_CUSTOM_REPO_URL="https://source.codeaurora.org/external/imx/uboot-imx.git"
 BR2_TARGET_UBOOT_CUSTOM_REPO_VERSION="rel_imx_4.9.x_1.0.0_ga"
 BR2_TARGET_UBOOT_FORMAT_IMX=y
+BR2_TARGET_UBOOT_NEEDS_DTC=y