Notify: remove Led class

This class didn't add any functionality beyond what the NotifyDevice class
already provided so in keeping with our desire to keep things simple we
can remove this class

libraries/AP_Notify/Led.h

@@ -1,37 +0,0 @@
-/*
- *  AP_Notify Library. 
- * based upon a prototype library by David "Buzz" Bussenschutt.
- */
-
-/*
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation, either version 3 of the License, or
-   (at your option) any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef __LED_H__
-#define __LED_H__
-
-#include <AP_HAL.h>
-#include "NotifyDevice.h"
-
-class Led: public NotifyDevice {
-public:
-    virtual ~Led() {}
-    // init - initialised the LED
-    virtual bool init(void) = 0;
-    // update - updates led according to timed_updated.  Should be
-    // called at 50Hz
-    virtual void update() = 0;
-};
-
-#endif //__LED_H__