VT-d: fix ia64 build

The identifier `dest_LowestPrio' is defined on only x86.

Signed-off-by: KUWAMURA Shin'ya <kuwa@jp.fujitsu.com>

xen/drivers/passthrough/vtd/intremap.c

@@ -322,8 +322,12 @@ static int ioapic_rte_to_remap_entry(struct iommu *iommu,
         new_ire.lo.dm = new_rte.dest_mode;
         new_ire.lo.tm = new_rte.trigger;
         new_ire.lo.dlm = new_rte.delivery_mode;
+#ifdef CONFIG_X86
         /* Hardware require RH = 1 for LPR delivery mode */
         new_ire.lo.rh = (new_ire.lo.dlm == dest_LowestPrio);
+#else
+        new_ire.lo.rh = 0;
+#endif
         new_ire.lo.avail = 0;
         new_ire.lo.res_1 = 0;
         new_ire.lo.vector = new_rte.vector;
@@ -635,8 +639,12 @@ static int msi_msg_to_remap_entry(
     new_ire.lo.dm = (msg->address_lo >> MSI_ADDR_DESTMODE_SHIFT) & 0x1;
     new_ire.lo.tm = (msg->data >> MSI_DATA_TRIGGER_SHIFT) & 0x1;
     new_ire.lo.dlm = (msg->data >> MSI_DATA_DELIVERY_MODE_SHIFT) & 0x1;
+#ifdef CONFIG_X86
     /* Hardware require RH = 1 for LPR delivery mode */
     new_ire.lo.rh = (new_ire.lo.dlm == dest_LowestPrio);
+#else
+    new_ire.lo.rh = 0;
+#endif
     new_ire.lo.avail = 0;
     new_ire.lo.res_1 = 0;
     new_ire.lo.vector = (msg->data >> MSI_DATA_VECTOR_SHIFT) &