microzed: u-boot needs host-dtc

defconfigs that use U-Boot 2015.07 need host-dtc to build
properly.

Signed-off-by: Davide Viti <d.viti@infosolution.it>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/microzed_defconfig

@@ -21,6 +21,7 @@ BR2_TARGET_UBOOT_BOARDNAME="zynq_microzed"
 BR2_TARGET_UBOOT_CUSTOM_VERSION=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2015.07"
 BR2_TARGET_UBOOT_PATCH="$(TOPDIR)/board/avnet/microzed/uboot"
+BR2_TARGET_UBOOT_NEEDS_DTC=y
 BR2_TARGET_UBOOT_FORMAT_DTB_IMG=y
 BR2_TARGET_UBOOT_SPL=y
 BR2_TARGET_UBOOT_ZYNQ_IMAGE=y