[ARM] use __used attribute

Use the newly introduced __used attribute in place of the deprecated
__attribute_used__.  Functionally the same.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm26/setup.h b/include/asm-arm26/setup.h
index 10fd07c..e825623 100644
--- a/include/asm-arm26/setup.h
+++ b/include/asm-arm26/setup.h
@@ -173,7 +173,7 @@
 	int (*parse)(const struct tag *);
 };
 
-#define __tag __attribute_used__ __attribute__((__section__(".taglist")))
+#define __tag __used __attribute__((__section__(".taglist")))
 #define __tagtable(tag, fn) \
 static struct tagtable __tagtable_##fn __tag = { tag, fn }