Change gcr.io location of the kube-cross images

Makefile

@@ -42,8 +42,8 @@ COMMIT_NO := $(shell git rev-parse HEAD 2> /dev/null || true)
 COMMIT ?= $(if $(shell git status --porcelain --untracked-files=no),"${COMMIT_NO}-dirty","${COMMIT_NO}")
 
 HYPERKIT_BUILD_IMAGE 	?= karalabe/xgo-1.12.x
-# NOTE: "latest" as of 2019-08-15. kube-cross images aren't updated as often as Kubernetes
-BUILD_IMAGE 	?= k8s.gcr.io/kube-cross:v$(GO_VERSION)-1
+# NOTE: "latest" as of 2020-02-26. kube-cross images aren't updated as often as Kubernetes
+BUILD_IMAGE 	?= us.gcr.io/k8s-artifacts-prod/build-image/kube-cross:v$(GO_VERSION)-1
 ISO_BUILD_IMAGE ?= $(REGISTRY)/buildroot-image
 KVM_BUILD_IMAGE ?= $(REGISTRY)/kvm-build-image:$(GO_VERSION)