Update ETH.cpp

Author: Jason2866

libraries/Ethernet/src/ETH.cpp

@@ -19,6 +19,10 @@
  */
 
 // Disable the automatic pin remapping of the API calls in this file
+
+#include "sdkconfig.h"
+#if CONFIG_ETH_ENABLED
+
 #define ARDUINO_CORE_BUILD
 
 #include "ETH.h"
@@ -1056,3 +1060,5 @@ size_t ETHClass::printDriverInfo(Print &out) const {
 }
 
 ETHClass ETH;
+
+#endif /* CONFIG_ETH_ENABLED */