menu: export menu_default_choice() function

Checking the default menu item and obtaining its data can
be useful in custom menu code. Export menu_default_choice()
function which serves this purpose.
Signed-off-by: NAnatolij Gustschin <agust@denx.de>

common/menu.c

@@ -176,7 +176,7 @@ static inline struct menu_item *menu_item_by_key(struct menu *m,
  * Set *choice to point to the default item's data, if any default item was
  * set, and returns 1. If no default item was set, returns -ENOENT.
  */
-static inline int menu_default_choice(struct menu *m, void **choice)
+int menu_default_choice(struct menu *m, void **choice)
 {
 	if (m->default_item) {
 		*choice = m->default_item->data;

doc/README.menu

@@ -65,6 +65,11 @@ int menu_item_add(struct menu *m, char *item_key, void *item_data);
  */
 int menu_default_set(struct menu *m, char *item_key);
 
+/*
+ * menu_default_choice() - Set *choice to point to the default item's data
+ */
+int menu_default_choice(struct menu *m, void **choice);
+
 /*
  * menu_get_choice() - Returns the user's selected menu entry, or the
  * default if the menu is set to not prompt or the timeout expires.

include/menu.h

@@ -29,6 +29,7 @@ int menu_get_choice(struct menu *m, void **choice);
 int menu_item_add(struct menu *m, char *item_key, void *item_data);
 int menu_destroy(struct menu *m);
 void menu_display_statusline(struct menu *m);
+int menu_default_choice(struct menu *m, void **choice);
 
 #if defined(CONFIG_MENU_SHOW)
 int menu_show(int bootdelay);