TFTP: add tftpsrv command

Signed-off-by: Luca Ceresoli <luca.ceresoli@comelit.it>
Cc: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
diff --git a/README b/README
index 6f3748d..ed73981 100644
--- a/README
+++ b/README
@@ -709,6 +709,7 @@
 					  (requires CONFIG_CMD_MEMORY)
 		CONFIG_CMD_SOURCE	  "source" command Support
 		CONFIG_CMD_SPI		* SPI serial bus support
+		CONFIG_CMD_TFTPSRV	* TFTP transfer in server mode
 		CONFIG_CMD_USB		* USB support
 		CONFIG_CMD_VFD		* VFD support (TRAB)
 		CONFIG_CMD_CDP		* Cisco Discover Protocol support