s390/topology: remove sysinfo header include, add forward declaration instead

Any change to sysinfo.h causes a whole kernel recompile since sysinfo.h is
included by topology.h, which again is used nearly everywhere.
So remove that include and add a forward declaration instead.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/topology.h b/arch/s390/include/asm/topology.h
index 0837de8..1e6c446 100644
--- a/arch/s390/include/asm/topology.h
+++ b/arch/s390/include/asm/topology.h
@@ -2,8 +2,8 @@
 #define _ASM_S390_TOPOLOGY_H
 
 #include <linux/cpumask.h>
-#include <asm/sysinfo.h>
 
+struct sysinfo_15_1_x;
 struct cpu;
 
 #ifdef CONFIG_SCHED_BOOK