cmd: thordown: Fix spelling of download.

Signed-off-by: Vagrant Cascadian <vagrant@debian.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
diff --git a/cmd/thordown.c b/cmd/thordown.c
index ce3660d..19ae672 100644
--- a/cmd/thordown.c
+++ b/cmd/thordown.c
@@ -65,7 +65,7 @@
 U_BOOT_CMD(thordown, CONFIG_SYS_MAXARGS, 1, do_thor_down,
 	   "TIZEN \"THOR\" downloader",
 	   "<USB_controller> <interface> <dev>\n"
-	   "  - device software upgrade via LTHOR TIZEN dowload\n"
+	   "  - device software upgrade via LTHOR TIZEN download\n"
 	   "    program via <USB_controller> on device <dev>,\n"
 	   "	attached to interface <interface>\n"
 );