added display support for RAK4631, removed Wire.begin(int, int) from nrf52 devices, cosmetic changes

src/helpers/nrf52/TechoBoard.cpp

@@ -26,11 +26,7 @@ void TechoBoard::begin() {
 
   pinMode(PIN_VBAT_READ, INPUT);
 
-#if defined(PIN_BOARD_SDA) && defined(PIN_BOARD_SCL)
-  Wire.begin(PIN_BOARD_SDA, PIN_BOARD_SCL);
-#else
   Wire.begin();
-#endif
 
   pinMode(SX126X_POWER_EN, OUTPUT);
   digitalWrite(SX126X_POWER_EN, HIGH);