Add RGB_LED_Test example

This example tests LEDR, LEDB and LEDG, accessed via WiFiNINA module.
Credit of @JAndrassy
Check earlephilhower/arduino-pico#404

Author: khoih-prog

examples/RGB_LED_Test/RGB_LED_Test.ino

@@ -0,0 +1,67 @@
+/****************************************************************************************************************************
+  RGB_LED_Test.ino
+
+  This example tests LEDR, LEDB and LEDG, accessed via WiFiNINA module.
+  Credit of https://github.com/jandrassy
+  Check https://github.com/earlephilhower/arduino-pico/pull/404
+
+  Built by Khoi Hoang https://github.com/khoih-prog/WiFiNINA_Generic
+  Licensed under GPLv3 license
+
+  Copyright (c) 2018 Arduino SA. All rights reserved.
+  Copyright (c) 2011-2014 Arduino LLC.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*****************************************************************************************************************************/
+
+//#include <WiFiNINA.h>
+#include <WiFiNINA_Generic.h>
+
+void setup() 
+{
+  Serial.begin(115200);
+  while (!Serial);
+
+  Serial.print("RGB_LED_Test on ");
+  Serial.print(BOARD_NAME);
+  Serial.print(" using ");
+
+#if __has_include("WiFiNINA.h")
+  Serial.println("WiFiNINA Library");
+#elif __has_include("WiFiNINA_Generic.h")
+  Serial.println("WiFiNINA_Generic Library");
+#else
+  #error Error. No WiFiNINA or WiFiNINA_Generic included
+#endif  
+
+  pinMode(LEDR, OUTPUT);
+  pinMode(LEDG, OUTPUT);
+  pinMode(LEDB, OUTPUT);
+}
+
+void loop() 
+{
+   digitalWrite(LEDR,HIGH);   // Turn On RED LED
+   delay(250);
+   digitalWrite(LEDR,LOW);    // Turn Off RED LED
+
+   digitalWrite(LEDG,HIGH);   // Turn On GREEN LED
+   delay(250);
+   digitalWrite(LEDG,LOW);    // Turn Off GREEN LED
+
+   digitalWrite(LEDB,HIGH);   // Turn On BLUE LED
+   delay(250);
+   digitalWrite(LEDB,LOW);    // Turn Off BLUE LED
+}