Refactor autoinit code

src/drivers/tm4c.h

@@ -15,21 +15,8 @@ struct mg_tcpip_driver_tm4c_data {
   int mdc_cr;  // Valid values: -1, 0, 1, 2, 3
 };
 
-#ifndef MG_MAC_ADDRESS
-#define MG_MAC_ADDRESS MG_MAC_ADDRESS_RANDOM
-#endif
-
 #ifndef MG_DRIVER_MDC_CR
 #define MG_DRIVER_MDC_CR 1
 #endif
 
-#define MG_TCPIP_DRIVER_DATA                                \
-  static struct mg_tcpip_driver_tm4c_data driver_data = { \
-      .mdc_cr = MG_DRIVER_MDC_CR,                            \
-  };
-
-#define MG_TCPIP_DRIVER_CODE &mg_tcpip_driver_tm4c
-#define MG_TCPIP_DRIVER_NAME "tm4c"
-
-
 #endif