Avoid PreP target kernel freeze waiting for IRQs.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3414 c046a42c-6fe2-441c-8c8c-71466251a162

hw/i8259.c

@@ -164,7 +164,7 @@ void pic_update_irq(PicState2 *s)
     }
 
 /* all targets should do this rather than acking the IRQ in the cpu */
-#if defined(TARGET_MIPS)
+#if defined(TARGET_MIPS) || defined(TARGET_PPC)
     else {
         qemu_irq_lower(s->parent_irq);
     }