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>
diff --git a/net/tftp.c b/net/tftp.c
index d6744bc..704b20b 100644
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -10,6 +10,7 @@
 #include <efi_loader.h>
 #include <env.h>
 #include <image.h>
+#include <led.h>
 #include <lmb.h>
 #include <log.h>
 #include <mapmem.h>
@@ -185,6 +186,7 @@
 #ifdef CONFIG_CMD_TFTPPUT
 	tftp_put_final_block_sent = 0;
 #endif
+	led_activity_blink();
 }
 
 #ifdef CONFIG_CMD_TFTPPUT
@@ -294,6 +296,9 @@
 			time_start * 1000, "/s");
 	}
 	puts("\ndone\n");
+
+	led_activity_off();
+
 	if (!tftp_put_active)
 		efi_set_bootdev("Net", "", tftp_filename,
 				map_sysmem(tftp_load_addr, 0),