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/esd/pmc405/pmc405.c b/board/esd/pmc405/pmc405.c
index c0781dc..975b6d6 100644
--- a/board/esd/pmc405/pmc405.c
+++ b/board/esd/pmc405/pmc405.c
@@ -203,6 +203,6 @@
 }
 U_BOOT_CMD(
 	cantest,	3,	1,	do_cantest,
-	"cantest - Test CAN controller",
+	"Test CAN controller",
 	NULL
 	);