target-ppc: add TLB_NEED_LOCAL_FLUSH flag

Introduces bit-flag in CPUPPCState::tlb_need_flush:

  TLB_NEED_LOCAL_FLUSH (0x1) - Flush local tlb

This would indicate a pending local tlb flush (isync instructions,
interrupts, ...)

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
index 8118143..1f52b64 100644
--- a/target-ppc/mmu-hash64.c
+++ b/target-ppc/mmu-hash64.c
@@ -110,7 +110,7 @@
              *      and we still don't have a tlb_flush_mask(env, n, mask)
              *      in QEMU, we just invalidate all TLBs
              */
-            env->tlb_need_flush = 1;
+            env->tlb_need_flush |= TLB_NEED_LOCAL_FLUSH;
         }
     }
 }
@@ -132,7 +132,7 @@
          *      and we still don't have a tlb_flush_mask(env, n, mask)
          *      in QEMU, we just invalidate all TLBs
          */
-        env->tlb_need_flush = 1;
+        env->tlb_need_flush |= TLB_NEED_LOCAL_FLUSH;
     }
 }