build: qsdk-ipq-*: include dtc in PATH before calling mkimage

Use 'dtc' from kernel sources instead of relying on host tool.

Fixes: bf4630e5ad ("build: add helpers for generating QSDK sysupgrade compatible images")
Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

include/image-commands.mk

@@ -297,14 +297,14 @@ endef
 define Build/qsdk-ipq-factory-nand
 	$(TOPDIR)/scripts/mkits-qsdk-ipq-image.sh \
 		$@.its ubi $@
-	mkimage -f $@.its $@.new
+	PATH=$(LINUX_DIR)/scripts/dtc:$(PATH) mkimage -f $@.its $@.new
 	@mv $@.new $@
 endef
 
 define Build/qsdk-ipq-factory-nor
 	$(TOPDIR)/scripts/mkits-qsdk-ipq-image.sh \
 		$@.its hlos $(IMAGE_KERNEL) rootfs $(IMAGE_ROOTFS)
-	mkimage -f $@.its $@.new
+	PATH=$(LINUX_DIR)/scripts/dtc:$(PATH) mkimage -f $@.its $@.new
 	@mv $@.new $@
 endef