tftp: implement support for LED activity

Implement support for LED activity. If the feature is enabled,
make the defined ACTIVITY LED to signal traffic.

Also turn the ACTIVITY LED OFF if a CTRL-C is detected in the main
net loop function.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

net/net.c

@@ -87,6 +87,7 @@
 #include <env_internal.h>
 #include <errno.h>
 #include <image.h>
+#include <led.h>
 #include <log.h>
 #include <net.h>
 #include <net6.h>
@@ -664,6 +665,9 @@ restart:
 			/* Invalidate the last protocol */
 			eth_set_last_protocol(BOOTP);
 
+			/* Turn off activity LED if triggered */
+			led_activity_off();
+
 			puts("\nAbort\n");
 			/* include a debug print as well incase the debug
 			   messages are directed to stderr */