microblaze: Invalidate dcache before enabling it

We found that on write-trough kernel is necessary to do that invalidation.
One WB is possible to use invalidation too.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c
index 5372b24..bb8c4b9 100644
--- a/arch/microblaze/kernel/setup.c
+++ b/arch/microblaze/kernel/setup.c
@@ -54,6 +54,7 @@
 
 	microblaze_cache_init();
 
+	invalidate_dcache();
 	enable_dcache();
 
 	invalidate_icache();