kernel: Switch to mkdtboimg.py

Change-Id: I6f444a3e2265f163e84eaf00d054697dbcf0f803
diff --git a/build/tasks/kernel.mk b/build/tasks/kernel.mk
index 90a76bc..7ca3e9a 100644
--- a/build/tasks/kernel.mk
+++ b/build/tasks/kernel.mk
@@ -305,7 +305,7 @@
 	@echo "Building dtbo.img"
 	$(call make-dtbo-target,$(KERNEL_DEFCONFIG))
 	$(call make-dtbo-target,dtbs)
-	$(MKDTIMG) create $@ --page_size=$(BOARD_KERNEL_PAGESIZE) $(shell find $(DTBO_OUT)/arch/$(KERNEL_ARCH)/boot/dts -type f -name "*.dtbo" | sort)
+	$(MKDTBOIMG) create $@ --page_size=$(BOARD_KERNEL_PAGESIZE) $(shell find $(DTBO_OUT)/arch/$(KERNEL_ARCH)/boot/dts -type f -name "*.dtbo" | sort)
 else
 $(BOARD_PREBUILT_DTBOIMAGE):
 	@echo "Building dtbo.img"