Changed 'built-in' LED used with Zephir boards from RED to GREEN

[bogdanarduino]

In ArduinoCore-zephyr\cores\arduino\Arduino.h, the built-in LED index was changed from 0 (RED) to 1 (GREEN).

[pillo79]

This PR is changing a global default, which must be available even on boards that only have 1 LED defined.
Please fix this by setting LED_BUILTIN to the appropriate number or macro in each variant (variants/xxx/pins_arduino.h).

[sebromero]

@pillo79 @bogdanarduino Maybe instead of changing it in the variant file, it might be cleaner to change it in the device tree overlay? I suppose builtin-led-gpios can have duplicate entries. So, the first index could always refer to the BUILTIN_LED, while the other entries are for RGB etc. e.g. for Giga it could be:

builtin-led-gpios = <&gpioj 13 GPIO_ACTIVE_LOW> // Green
                    <&gpioi 12 GPIO_ACTIVE_LOW>, // Red
                    <&gpioj 13 GPIO_ACTIVE_LOW>, // Green
                    <&gpioe 3 GPIO_ACTIVE_LOW>; // Blue

Wdyt?

[facchinm]

Compeltely agree with @sebromero , the right way to tackle this is via device tree

[bogdanarduino]

Thank you all for your feedback! Please recheck the updated fix when you have time.