Disable MFLAGS and MAKEFLAGS for make-kpkg

Change-Id: I8f4b204c1cf6c56223b6ef09871aadf9311d4377
diff --git a/kernel.mk b/kernel.mk
index 8f74b27..a2e7259 100644
--- a/kernel.mk
+++ b/kernel.mk
@@ -41,7 +41,7 @@
 	mkdir -p $(KERNEL_OUT_DIR)
 	cp -afs $(ROOTDIR)/linux-imx/* $(KERNEL_OUT_DIR)
 	make -f $(ROOTDIR)/build/kernel.mk $(KERNEL_OUT_DIR)/.config
-	cd $(KERNEL_OUT_DIR); make-kpkg --rootcmd fakeroot --arch arm64 \
+	cd $(KERNEL_OUT_DIR); MFLAGS="" MAKEFLAGS="" make-kpkg --rootcmd fakeroot --arch arm64 \
 		--cross-compile $(TOOLCHAIN) --revision 1 --append-to-version=-aiy \
 		-j $(shell nproc) --overlay-dir=$(ROOTDIR)/build/kernel-overlay \
 		kernel_image kernel_headers