autoip: Make max-conflics and rate-limit configurable

These constants are defined in RFC-3927 (10 conflicts before rate
limiting and 60 seconds between attempts) and are not intended to be
configurable. We cannot pass BCT without adjusting these params, though.

Ref IDF-4843

src/include/lwip/prot/autoip.h

@@ -59,8 +59,13 @@ extern "C" {
 #define ANNOUNCE_NUM            2   /*          (number of announcement packets)       */
 #define ANNOUNCE_INTERVAL       2   /* seconds  (time between announcement packets)    */
 #define ANNOUNCE_WAIT           2   /* seconds  (delay before announcing)              */
+#if ESP_LWIP
+#define MAX_CONFLICTS           LWIP_AUTOIP_MAX_CONFLICTS        /*          (max conflicts before rate limiting) */
+#define RATE_LIMIT_INTERVAL     LWIP_AUTOIP_RATE_LIMIT_INTERVAL  /* seconds  (delay between successive attempts) */
+#else
 #define MAX_CONFLICTS           10  /*          (max conflicts before rate limiting)   */
 #define RATE_LIMIT_INTERVAL     60  /* seconds  (delay between successive attempts)    */
+#endif
 #define DEFEND_INTERVAL         10  /* seconds  (min. wait between defensive ARPs)     */
 
 /* AutoIP client states */