Revert change to multi-arch operator

The operator Dockerfile was not building as multi-arch due to
the movement of the ARGS for platforms.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Author: alexellis

Dockerfile

@@ -1,10 +1,10 @@
+FROM --platform=${BUILDPLATFORM:-linux/amd64} teamserverless/license-check:0.3.9 as license-check
+FROM --platform=${BUILDPLATFORM:-linux/amd64} golang:1.13 as builder
 ARG TARGETPLATFORM
 ARG BUILDPLATFORM
 ARG TARGETOS
 ARG TARGETARCH
 
-FROM --platform=${BUILDPLATFORM:-linux/amd64} teamserverless/license-check:0.3.9 as license-check
-FROM --platform=${BUILDPLATFORM:-linux/amd64} golang:1.13 as builder
 
 ARG Version
 ARG GitCommit