powerpc: Wire renameat2() syscall

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index 3ddf702..ea4dc3a 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -361,3 +361,4 @@
 SYSCALL(ni_syscall) /* sys_kcmp */
 SYSCALL_SPU(sched_setattr)
 SYSCALL_SPU(sched_getattr)
+SYSCALL_SPU(renameat2)