powerpc: apply recent changes to merged code

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/lib/locks.c b/arch/powerpc/lib/locks.c
index 4b8c5ad..3794715 100644
--- a/arch/powerpc/lib/locks.c
+++ b/arch/powerpc/lib/locks.c
@@ -17,6 +17,7 @@
 #include <linux/spinlock.h>
 #include <linux/module.h>
 #include <linux/stringify.h>
+#include <linux/smp.h>
 
 /* waiting for a spinlock... */
 #if defined(CONFIG_PPC_SPLPAR) || defined(CONFIG_PPC_ISERIES)