Retrieve an extension identified by a key (string) from the specified list of video modes
#include <wfdqnx/wfdcfg.h>
struct wfdcfg_keyval* wfdcfg_mode_list_get_extension(const struct wfdcfg_mode_list *list, const char *key)
The extension is valid between the time you create and destroy the list.
Pointer to wfdcfg_keyval if the extension was found; NULL if the extension was not found. It's considered acceptable for a list to have no extensions.