There is an updated pull request by q66 against master on the void-packages repository

https://github.com/void-power/void-packages grub-osx
https://github.com/void-linux/void-packages/pull/12046

grub: patch out creation of OS X menu entries on non-x86
@pullmoll, can you test this on your Mac machine? It should do the right thing.

A patch file from https://github.com/void-linux/void-packages/pull/12046.patch is attached