Use docker buildx to build docker image

xref: https://community.arm.com/developer/tools-software/tools/b/tools-software-ides-blog/posts/getting-started-with-docker-for-arm-on-linux

Signed-off-by: Tamal Saha <tamal@appscode.com>

Author: tamalsaha

Makefile

@@ -215,7 +215,7 @@ bin/.container-$(DOTFILE_IMAGE)-%: bin/$(OS)_$(ARCH)/$(BIN) $(DOCKERFILE_%)
 	    -e 's|{RESTIC_VER}|$(RESTIC_VER)|g'         \
 	    -e 's|{NEW_RESTIC_VER}|$(NEW_RESTIC_VER)|g' \
 	    $(DOCKERFILE_$*) > bin/.dockerfile-$*-$(OS)_$(ARCH)
-	@docker build --pull -t $(IMAGE):$(TAG_$*) -f bin/.dockerfile-$*-$(OS)_$(ARCH) .
+	@DOCKER_CLI_EXPERIMENTAL=enabled docker buildx build --platform $(OS)/$(ARCH) --load --pull -t $(IMAGE):$(TAG_$*) -f bin/.dockerfile-$*-$(OS)_$(ARCH) .
 	@docker images -q $(IMAGE):$(TAG_$*) > $@
 	@echo
 

go.sum

@@ -444,5 +444,5 @@ sigs.k8s.io/kustomize v2.0.3+incompatible/go.mod h1:MkjgH3RdOWrievjo6c9T245dYlB5
 sigs.k8s.io/structured-merge-diff v0.0.0-20190302045857-e85c7b244fd2/go.mod h1:wWxsB5ozmmv/SG7nM11ayaAW51xMvak/t1r0CSlcokI=
 sigs.k8s.io/yaml v1.1.0 h1:4A07+ZFc2wgJwo8YNlQpr1rVlgUDlxXHhPJciaPY5gs=
 sigs.k8s.io/yaml v1.1.0/go.mod h1:UJmg0vDUVViEyp3mgSv9WPwZCDxu4rQW1olrI1uml+o=
-stash.appscode.dev/stash v0.9.0-rc.0 h1:vSSzKdoQWS4hKLd7cVWyL6tkTwH8aVEse4RP7kAe/ec=
+stash.appscode.dev/stash v0.9.0-rc.0 h1:GhzBnqHYBgq+2bcuwsDK3nhq2PPEhGkBH0EFAXp2OmY=
 stash.appscode.dev/stash v0.9.0-rc.0/go.mod h1:/YjAPx/9E4ScxWea1mbJC6qx9TomhqS83AUy2LufVVk=