Add beep source code and update led.h

guowenxue

2018-10-14 48e47b5212ace2dcb83379d3502b11f64ef4204d

 modules/c/led.h

@@ -2,7 +2,7 @@
 *      Copyright:  (C) 2018 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  led.c
 *       Filename:  led.h
 *    Description:  This file is used to control RGB 3-colours LED
 *
 *     pi@raspberrypi:~ $ gpio readall show BCM and wPi pinmap