[hci] Allow tab key to be used to cycle through UI elements

Add support for wraparound scrolling and allow the tab key to be used
to move forward through a list of elements, wrapping back around to
the beginning of the list on overflow.

This is mildly useful for a menu, and likely to be a strong user
expectation for an interactive form.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/hci/tui/settings_ui.c

@@ -381,8 +381,8 @@ static void select_settings ( struct settings_ui *ui,
 static int main_loop ( struct settings *settings ) {
 	struct settings_ui ui;
 	unsigned int previous;
+	unsigned int move;
 	int redraw = 1;
-	int move;
 	int key;
 	int rc;