[POWERPC] Disable vDSO support for ARCH=ppc where it's not implemented

Signed-off-by: NWolfgang Denk <wd@denx.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/kernel/vdso.c

@@ -766,7 +766,9 @@ static int __init vdso_init(void)
 
 	return 0;
 }
+#ifdef CONFIG_PPC_MERGE
 arch_initcall(vdso_init);
+#endif
 
 int in_gate_area_no_task(unsigned long addr)
 {