AP_HAL_AVR: Do not init HAL's dataflash

libraries/AP_HAL_AVR/HAL_AVR.cpp

@@ -18,6 +18,5 @@ void HAL_AVR::init(void* opts) const {
     i2c->begin();
     i2c->setTimeout(100);
     analogin->init(NULL);
-    dataflash->init(NULL);
 };