configurable pins

[ponty]

It would be more flexible to have configurable pins instead of hardcoded pins because:

• IDB0XA1_D13_PATCH is confusing
• there are other alternate pins on X-NUCLEO-IDB05A1 (CS, IRQ)
• custom designed boards can have different pins
• it is nice to see the pin definitions in the main program

I would like to move this code block in my main program without changing the lib:

BlueNRGDevice bluenrgDeviceInstance(IDB0XA1_PIN_SPI_MOSI,
                                    IDB0XA1_PIN_SPI_MISO,
                                    IDB0XA1_PIN_SPI_SCK,
                                    IDB0XA1_PIN_SPI_nCS,
                                    IDB0XA1_PIN_SPI_RESET,
                                    IDB0XA1_PIN_SPI_IRQ);