[arch-releng] Pretty EFI splash

[Sven-Hendrik Haase]

I think it would be cool to have the EFI splash screen show the same
graphical image that the syslinux boot loader has. I played around a little
to try to get it to work but failed. I used the systemd test as a basis for
that [1].

Thoughts on pretty EFI boot loader?

[1] https://github.com/systemd/systemd/blob/dd8352659c9428b196706d04399eec
106a8917ed/test/test-efi-create-disk.sh