Revert "kernel: Set full path to DTC"

This reverts commit dfddddc97e4671a2cb18873ca715ce6df94614ac.
diff --git a/build/tasks/kernel.mk b/build/tasks/kernel.mk
index 0253d61..bfaebce 100644
--- a/build/tasks/kernel.mk
+++ b/build/tasks/kernel.mk
@@ -209,8 +209,6 @@
 
 KERNEL_ADDITIONAL_CONFIG_OUT := $(KERNEL_OUT)/.additional_config
 
-KERNEL_MAKE_FLAGS += DTC=$(KERNEL_BUILD_OUT_PREFIX)$(DTC)
-
 # Internal implementation of make-kernel-target
 # $(1): output path (The value passed to O=)
 # $(2): target to build (eg. defconfig, modules, dtbo.img)