Add driver init to mg_mgr_init()

src/drivers/tm4c.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#if MG_ENABLE_TCPIP && defined(MG_ENABLE_DRIVER_TM4C) && MG_ENABLE_DRIVER_TM4C
+
 struct mg_tcpip_driver_tm4c_data {
   // MDC clock divider. MDC clock is derived from SYSCLK, must not exceed 2.5MHz
   //    SYSCLK range   DIVIDER   mdc_cr VALUE
@@ -12,3 +14,22 @@ struct mg_tcpip_driver_tm4c_data {
   //    0x4-0xF Reserved
   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