powerpc: Move smp_mpic_message_pass into mpic.c

Having it here rather than in arch/ppc64/kernel/smp.c means that
we can use it on 32-bit SMP systems easily with ARCH=powerpc.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 02b4d24..3948e75 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -904,4 +904,25 @@
 
 	printk("IPIs requested... \n");
 }
+
+void smp_mpic_message_pass(int target, int msg)
+{
+	/* make sure we're sending something that translates to an IPI */
+	if ((unsigned int)msg > 3) {
+		printk("SMP %d: smp_message_pass: unknown msg %d\n",
+		       smp_processor_id(), msg);
+		return;
+	}
+	switch (target) {
+	case MSG_ALL:
+		mpic_send_ipi(msg, 0xffffffff);
+		break;
+	case MSG_ALL_BUT_SELF:
+		mpic_send_ipi(msg, 0xffffffff & ~(1 << smp_processor_id()));
+		break;
+	default:
+		mpic_send_ipi(msg, 1 << target);
+		break;
+	}
+}
 #endif /* CONFIG_SMP */