kconfig: remove allnoconfig_y option

Now that the only user, CONFIG_EMBEDDED has stopped using this option,
remove it entirely.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/lkc.h

@@ -96,7 +96,6 @@ struct property *menu_add_prompt(enum prop_type type, char *prompt, struct expr
 void menu_add_expr(enum prop_type type, struct expr *expr, struct expr *dep);
 void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep);
 void menu_add_option_modules(void);
-void menu_add_option_allnoconfig_y(void);
 void menu_finalize(struct menu *parent);
 void menu_set_type(int type);