[POWERPC] Add strncmp to arch/ppc

Commit 0119536cd314ef95553604208c25bc35581f7f0a added an assembly
version of strncmp to PowerPC.  However, it changed a common header
file between arch/ppc and arch/powerpc without adding strncmp to
arch/ppc.  This fixes that omission so that arch/ppc links again.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc/kernel/ppc_ksyms.c b/arch/ppc/kernel/ppc_ksyms.c
index 2ba659f..d9036ef 100644
--- a/arch/ppc/kernel/ppc_ksyms.c
+++ b/arch/ppc/kernel/ppc_ksyms.c
@@ -88,6 +88,7 @@
 EXPORT_SYMBOL(strcat);
 EXPORT_SYMBOL(strlen);
 EXPORT_SYMBOL(strcmp);
+EXPORT_SYMBOL(strncmp);
 
 EXPORT_SYMBOL(csum_partial);
 EXPORT_SYMBOL(csum_partial_copy_generic);