draft: firmware/efi: enable the zboot EFI loader for ARM64

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2170602

Enable the EFI zboot firmware loader for ARM64. This will allow unified kernel images to load on ARM64 server platforms with UEFI.

Signed-off-by: Mark Langsdorf mlangsdo@redhat.com