Merge pull request #2989 from rgregg/fix-nrf52-ethernet-build

Fix nRF52 builds broken by unconditional RAK Ethernet include

Author: liamcottle

src/helpers/nrf52/SerialEthernetInterface.cpp

@@ -1,3 +1,5 @@
+#ifdef ETHERNET_ENABLED
+
 #include "SerialEthernetInterface.h"
 #include "EthernetMac.h"
 #include <SPI.h>
@@ -262,3 +264,5 @@ bool SerialEthernetInterface::isConnected() const {
 void SerialEthernetInterface::loop() {
   Ethernet.maintain();
 }
+
+#endif // ETHERNET_ENABLED

src/helpers/nrf52/SerialEthernetInterface.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#ifdef ETHERNET_ENABLED
+
 #include "helpers/BaseSerialInterface.h"
 #include <SPI.h>
 #include <RAK13800_W5100S.h>
@@ -76,3 +78,5 @@ class SerialEthernetInterface : public BaseSerialInterface {
   #define ETHERNET_DEBUG_PRINTLN(...) {}
   #define ETHERNET_DEBUG_PRINT_IP(...) {}
 #endif
+
+#endif // ETHERNET_ENABLED