[OpenBIOS] Regression in booting HelenOS/sparc64

[Artyom Tarasenko]

As of today qemu git/master and OpenBIOS/trunk can't boot
HelenOS-0.4.3-sparc64-ultra.iso .

$ sparc64-softmmu/qemu-system-sparc64 -m 512 -boot d -cdrom
/mnt/terra/projects/sparc-images/HelenOS-0.4.3-sparc64-ultra.iso -bios
openbios-sparc64-trunk
Unassigned mem access to 000001ff00700000 from 000000000041c00c
^^^Booting stops here

It looks like the regression is coming form the OpenBIOS, because
older qemu versions can boot HelenOS with older OpenBIOS, but not with
trunk. Can't check other way around because current qemu doesn't start
with older OpenBIOS at all.