[net][lwip] Add missing reference file for LWIP 1.4.1

components/net/lwip-1.4.1/src/arch/sys_arch.c

@@ -26,6 +26,7 @@
 #include "netif/ethernetif.h"
 #include "lwip/sio.h"
 #include <lwip/init.h>
+#include "lwip/inet.h"
 
 #include <string.h>
 

components/net/lwip-1.4.1/src/netif/ethernetif.c

@@ -63,6 +63,7 @@
 
 #include "netif/etharp.h"
 #include "netif/ethernetif.h"
+#include "lwip/inet.h"
 
 #define netifapi_netif_set_link_up(n)      netifapi_netif_common(n, netif_set_link_up, NULL)
 #define netifapi_netif_set_link_down(n)    netifapi_netif_common(n, netif_set_link_down, NULL)