Disable LAN867x PHY by default

Author: MATTYGILO

boards/MICROLITE/mpconfigboard.h

@@ -1,2 +1,8 @@
 #define MICROPY_HW_BOARD_NAME "ESP32 module (microlite)"
 #define MICROPY_HW_MCU_NAME "ESP32"
+
+// Disable LAN867x Ethernet PHY by default as the required header may not be
+// available with all ESP-IDF versions.
+#ifndef PHY_LAN867X_ENABLED
+#define PHY_LAN867X_ENABLED (0)
+#endif