ARM: amba: make amba_driver id_table const

Now that the bus level code deals with a const id table, we can also
make the ID table in the amba_driver structure also const.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

include/linux/amba/bus.h

@@ -48,7 +48,7 @@ struct amba_driver {
 	void			(*shutdown)(struct amba_device *);
 	int			(*suspend)(struct amba_device *, pm_message_t);
 	int			(*resume)(struct amba_device *);
-	struct amba_id		*id_table;
+	const struct amba_id	*id_table;
 };
 
 enum amba_vendor {