Command usage cleanup

Remove command name from all command "usage" fields and update
common/command.c to display "name - usage" instead of
just "usage". Also remove newlines from command usage fields.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/common/cmd_display.c b/common/cmd_display.c
index 982e09d..4102424 100644
--- a/common/cmd_display.c
+++ b/common/cmd_display.c
@@ -71,7 +71,7 @@
 
 U_BOOT_CMD(
 	display,	CONFIG_SYS_MAXARGS,	1,	do_display,
-	"display- display string on dot matrix display\n",
+	"display string on dot matrix display",
 	"[<string>]\n"
 	"    - with <string> argument: display <string> on dot matrix display\n"
 	"    - without arguments: clear dot matrix display\n"