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/board/amcc/yucca/cmd_yucca.c b/board/amcc/yucca/cmd_yucca.c
index 5198317..d2ca257 100644
--- a/board/amcc/yucca/cmd_yucca.c
+++ b/board/amcc/yucca/cmd_yucca.c
@@ -281,6 +281,6 @@
 
 U_BOOT_CMD(
 	evb440spe,	3,	1,	do_evb440spe,
-	"evb440spe - program the serial device strap\n",
+	"program the serial device strap",
 	"wrclk [prom0|prom1] - program the serial device strap\n"
 );