PPC: 440: Default to 440EP CPU

Today we're exposing a Virtex 440 CPU to the guest despite the fact
that we're telling the guest that we're running on a 440EP one in the
device tree.

So let's better default to a real 440EP to make things synced again.
Signed-off-by: NAlexander Graf <agraf@suse.de>

hw/ppc440.c

@@ -48,7 +48,7 @@ CPUState *ppc440ep_init(MemoryRegion *address_space_mem, ram_addr_t *ram_size,
     qemu_irq *pci_irqs;
 
     if (cpu_model == NULL) {
-        cpu_model = "440-Xilinx"; // XXX: should be 440EP
+        cpu_model = "440EP";
     }
     env = cpu_init(cpu_model);
     if (!env) {