ncurses: fix build with musl libc toolchains

Signed-off-by: Florian Fainelli <florian@openwrt.org>

SVN-Revision: 35811

package/libs/ncurses/patches/200-fix_missing_include.patch

 --- a/ncurses/curses.priv.h
 +++ b/ncurses/curses.priv.h
-@@ -54,6 +54,10 @@ extern "C" {
+@@ -54,6 +54,11 @@ extern "C" {
  
  #include <ncurses_cfg.h>
  
 +#if NEED_WCHAR_H
++#include <stdarg.h>
 +#include <wchar.h>
 +#endif
 +