microblaze: Fix problem with removing zero length files

Adding one new line was recommended solution.
Test with make distclean

Tested-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/include/asm/user.h b/arch/microblaze/include/asm/user.h
index e69de29..8b13789 100644
--- a/arch/microblaze/include/asm/user.h
+++ b/arch/microblaze/include/asm/user.h
@@ -0,0 +1 @@
+