[S390] smp: setup smp_processor_id early

smp_processor_id() is supposed to work before setup_arch() gets called.
Before that smp_processor_id() may return just an arbitrary value that
is contained in the uninitialized boot lowcore.
So provide the arch function which will override the weak function in
init/main.c.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 93e5203..eebce7f 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -717,6 +717,12 @@
 {
 }
 
+void __init smp_setup_processor_id(void)
+{
+	S390_lowcore.cpu_nr = 0;
+	__cpu_logical_map[0] = stap();
+}
+
 /*
  * the frequency of the profiling timer can be changed
  * by writing a multiplier value into /proc/profile.