[IA64] Enable percpu vector domain for IA64_DIG

Add per-CPU vector domain support for IA64_DIG. It is enabled by
adding the "vector=percpu" boot option.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/irq_ia64.c

@@ -267,7 +267,7 @@ void __setup_vector_irq(int cpu)
 	}
 }
 
-#if defined(CONFIG_IA64_GENERIC)
+#if defined(CONFIG_SMP) && (defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG))
 static enum vector_domain_type {
 	VECTOR_DOMAIN_NONE,
 	VECTOR_DOMAIN_PERCPU