PPC 85xx QEMU: Don't use HID1

For the QEMU machine type, we can plug in either e500v2, e500mc, e5500
or e6500 style cores into the system. U-boot has to work with all of them.

So avoid using HID1 which is not available on e500mc systems to make sure
we don't trap on it.

Signed-off-by: Alexander Graf <agraf@suse.de>