New review comment by astralchan on void-packages repository

https://github.com/void-linux/void-packages/pull/41675#discussion_r1248581500

Comment:
Covering all cases could look like:

```sh
case "$XBPS_TARGET_MACHINE" in
    x86) arch="x86_32" ;;
    x86_64*) arch="x86_64" ;;
    armv7*) arch="arm64" ;;
    ppc*) arch="ppc64" ;;
   #.
   #.
   #.
   # etc
esac

make_build_args+=" arch=$arch"
```