[POWERPC] Add missing native dcr dcr_ind_lock spinlock

The include/asm-powerpc/dcr-native.h declares extern spinlock_t dcr_ind_lock;
but it's actually isn't defined. This patch adds a missing dcr_ind_lock.

Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
index 427027c..437e48d 100644
--- a/arch/powerpc/sysdev/dcr.c
+++ b/arch/powerpc/sysdev/dcr.c
@@ -137,5 +137,6 @@
 	h.token = NULL;
 }
 EXPORT_SYMBOL_GPL(dcr_unmap);
-
-#endif /* !defined(CONFIG_PPC_DCR_NATIVE) */
+#else	/* defined(CONFIG_PPC_DCR_NATIVE) */
+DEFINE_SPINLOCK(dcr_ind_lock);
+#endif	/* !defined(CONFIG_PPC_DCR_NATIVE) */