[S390] smp: external call vs. emergency signal

Use a sigp sense running to decide which signal processor order to use
for an ipi. If the target cpu is running use external call, if the target
cpu is not running use emergency signal.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/head31.S b/arch/s390/kernel/head31.S
index f21954b..d3f1ab7 100644
--- a/arch/s390/kernel/head31.S
+++ b/arch/s390/kernel/head31.S
@@ -92,7 +92,7 @@
 .LPG3:
 # check control registers
 	stctl	%c0,%c15,0(%r15)
-	oi	2(%r15),0x40		# enable sigp emergency signal
+	oi	2(%r15),0x60		# enable sigp emergency & external call
 	oi	0(%r15),0x10		# switch on low address protection
 	lctl	%c0,%c15,0(%r15)