config: make members feature specific

Channel and address are only sensible for boards that actually have a
transceiver.

sys/config/config.c

@@ -19,8 +19,10 @@
 #include <config.h>
 
 config_t sysconfig  = {
-    0,      ///< default ID
-    0,      ///< default radio address
-    0,      ///< default radio channel
-    "foobar", ///< default name
+    0,      /**< default ID */
+#ifdef HAS_RADIO
+    0,      /**< default radio address */
+    0,      /**< default radio channel */
+#endif
+    "foobar", /**< default name */
 };

sys/include/config.h

@@ -20,7 +20,9 @@
 #define CONFIG_H
 
 #include <stdint.h>
-#include "board.h"
+#ifdef HAS_RADIO
+#include "radio/types.h"
+#endif
 
 #ifdef __cplusplus
  extern "C" {
@@ -38,10 +40,12 @@ extern char configmem[];
  * @brief  Stores configuration data of the node.
  */
 typedef struct {
-    uint16_t id;                /**< unique node identifier          */
+    uint16_t id;                    /**< unique node identifier          */
+#ifdef HAS_RADIO
     radio_address_t radio_address;  /**< address for radio communication */
-    uint8_t radio_channel;      /**< current frequency               */
-    char name[CONFIG_NAME_LEN]; /**< name of the node                */
+    uint8_t radio_channel;          /**< current frequency               */
+#endif
+    char name[CONFIG_NAME_LEN];     /**< name of the node                */
 } config_t;
 
 /**