build: modify makefile to build multiarch locally

Author: maheckathorn

Makefile

@@ -13,11 +13,11 @@ export WORK_DIR = .
 build: build2
 
 build2:
-	docker build --build-arg http_proxy --build-arg https_proxy --build-arg no_proxy -t $(IMAGE_NAME):latest -f Dockerfile .
+	docker buildx build --platform linux/amd64,linux/arm64 --build-arg http_proxy --build-arg https_proxy --build-arg no_proxy -t $(IMAGE_NAME):latest -f Dockerfile .
 	docker tag $(IMAGE_NAME):latest $(IMAGE_NAME):2
 
 build3:
-	docker build --build-arg http_proxy --build-arg https_proxy --build-arg no_proxy --build-arg FIXBUF_VERSION=3.0.0.alpha2 -t $(IMAGE_NAME):3 -f Dockerfile .	
+	docker buildx build --platform linux/amd64,linux/arm64 --build-arg http_proxy --build-arg https_proxy --build-arg no_proxy --build-arg FIXBUF_VERSION=3.0.0.alpha2 -t $(IMAGE_NAME):3 -f Dockerfile .	
 
 test:
 	docker rm -f $(SOFTWARE_NAME)