powerpc: convert to generic helpers for IPI function calls

This converts ppc to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single().

ppc loses the timeout functionality of smp_call_function_mask() with
this change, as the generic code does not provide that.

Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index ebebc28..0fc830f 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -383,13 +383,11 @@
 			mb();
 			smp_message_recv(PPC_MSG_RESCHEDULE);
 		}
-#if 0
-		if (test_and_clear_bit(PPC_MSG_MIGRATE_TASK,
+		if (test_and_clear_bit(PPC_MSG_CALL_FUNC_SINGLE,
 				       &xics_ipi_message[cpu].value)) {
 			mb();
-			smp_message_recv(PPC_MSG_MIGRATE_TASK);
+			smp_message_recv(PPC_MSG_CALL_FUNC_SINGLE);
 		}
-#endif
 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 		if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK,
 				       &xics_ipi_message[cpu].value)) {