net: Add wget application

This commit adds a simple wget command that can download files
from http server.

The command syntax is
wget ${loadaddr} <path of the file from server>

Signed-off-by: Duncan Hare <DuncanCHare@yahoo.com>
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>

net/net.c

@@ -118,6 +118,7 @@
 #include "wol.h"
 #endif
 #include <net/tcp.h>
+#include <net/wget.h>
 
 /** BOOTP EXTENTIONS **/
 
@@ -517,6 +518,11 @@ restart:
 			nfs_start();
 			break;
 #endif
+#if defined(CONFIG_CMD_WGET)
+		case WGET:
+			wget_start();
+			break;
+#endif
 #if defined(CONFIG_CMD_CDP)
 		case CDP:
 			cdp_start();