net/igmp: Remove igmp_initialize

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

net/net_initialize.c

@@ -43,7 +43,6 @@
 #include "ieee802154/ieee802154.h"
 #include "can/can.h"
 #include "netlink/netlink.h"
-#include "igmp/igmp.h"
 #include "route/route.h"
 #include "usrsock/usrsock.h"
 
@@ -158,12 +157,6 @@ void net_initialize(void)
 #endif
 #endif
 
-#ifdef CONFIG_NET_IGMP
-  /* Initialize IGMP support */
-
-  igmp_initialize();
-#endif
-
 #ifdef CONFIG_NET_ROUTE
   /* Initialize the routing table */