stdio: constify "name" arg in public api

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/stdio_dev.h b/include/stdio_dev.h
index 83da4cd..82ad463 100644
--- a/include/stdio_dev.h
+++ b/include/stdio_dev.h
@@ -93,10 +93,10 @@
 int	stdio_init (void);
 void	stdio_print_current_devices(void);
 #ifdef CONFIG_SYS_STDIO_DEREGISTER
-int	stdio_deregister(char *devname);
+int	stdio_deregister(const char *devname);
 #endif
 struct list_head* stdio_get_list(void);
-struct stdio_dev* stdio_get_by_name(char* name);
+struct stdio_dev* stdio_get_by_name(const char* name);
 struct stdio_dev* stdio_clone(struct stdio_dev *dev);
 
 #ifdef CONFIG_ARM_DCC_MULTI