New comment by smorimoto on void-packages repository

https://github.com/void-linux/void-packages/pull/25665#issuecomment-726541992

Comment:
​Oh, we seem to have this:

https://github.com/void-linux/void-packages/blob/0baf47ac2fad9ca82a4bdc918e7976fa9f5824d9/common/environment/build-style/go.sh#L17-L29

So this might be enough for us:

```sh
if [ -z "$GOARM" ]; then
  make bin GOARCH="$GOARCH"
else
  make bin GOARCH="$GOARCH" GOARM="$GOARM"
fi
```

https://github.com/hashicorp/waypoint/blob/ee9443811c1ac724c24b4017dba1b97f6f1018d3/Makefile#L14