nrf24l01 driver: Explicitly enable AutoAck on setup()

src/driver/nrf24l01.cc

@@ -51,6 +51,9 @@ void Nrf24l01::setup()
 
 	setDataRate(RF24_1MBPS);
 
+	// Reset value is "enabled on all pipes"
+	setAutoAck(1);
+
 	toggleFeatures();
 	writeRegister(FEATURE, 0);
 	writeRegister(DYNPD, 0);
@@ -589,4 +592,4 @@ uint8_t Nrf24l01::flushTx(void)
 	return rxbuf[0];
 }
 
-Nrf24l01 nrf24l01;
\ No newline at end of file
+Nrf24l01 nrf24l01;